Learn a Drug a Day - Summary

Hey friends, sorry for not updating <Learn a Drug a Day> lately.
I was kind of busy with my own stuffs and also PHC training.

Since my PHC training is ongoing and new sems is going to start soon, I would like to put <Learn a Drug a Day> to an end temporarily. Because i would not have time to update ever since my new sems has been started.


Since we may not remember everything about the drugs at the moment, i think we should at least remember the indication of them. So, I have made a summary table for all the drugs that i had posted within this period which include the indications of all drugs. For you all to refresh and revise! 

No.	Drug Name	Indication
1.	Colchicine	-          For treatment and relief of pain in attacks of acute gouty arthritis. -          Treat familial Mediterranean fever -          Prophylaxis to prevent attacks of gout.
2.	Bumetanide	-          Treatment of edema associated with congestive heart failure, hepatic and renal disease, including the nephrotic syndrome. -          Control high blood pressure but does not cure it.
3.	Dobutamine	-          Positive inotrope used in cardiovascular decompensation secondary to loss of ventricular contractility as in CHF or after cardiac surgery. -          Positive inotrope used in CHF patients after acute myocardial infarction.
4.	Calcium acetate	-          Control of hyperphosphatemia in end stage renal failure and does not promote aluminum absorption.
5.	Risedronate sodium	-          Treatment and prevention of osteoporosis in postmenopausal women. -          Treatment of osteoporosis in men at high-risk fracture. -          Treat Paget's disease of bone.
6.	Desonide	-          Treatment of mild to moderate atopic dermatitis.
7.	Malathion	-          Indicated for patients infected with head lice and their ova. -          Indicated for patient infected with crab lice or scabies.
8.	Labetalol hydrochloride	-          Labetalol HCl tablets are indicated in the management of hypertension. -          Labetalol HCl injection is indicated for control of blood pressure in severe hypertension.
9.	Zopiclone	-          Short-term treatment of insomnia.
10.	Tetrabenazine	-          For the treatment of diseases, which cause jerky, irregular, uncontrollable movements such as Huntington’s chorea, senile chorea and hemiballismus. -          It helps to control the condition, but does not cure it.
11.	Guaifenesin	-          An expectorant used for the temporary relief of coughs caused by certain respiratory tract infections and other breathing illnesses.
12.	Clonidine	-          Mainly indicated in the treatment of hypertension. It controls high blood pressure but does not cure it. -          Treatment of dysmenorrhe, hypertensive crisis, Tourette's syndrome, attention deficit hyperactivity disorder, menopausal hot flashes, and alcohol and opiate (narcotic) withdrawal. -          Used and as an aid in smoking cessation therapy and to diagnose pheochromocytoma. -          Treatment of severe cancer pain and  prophylaxis of migraine.
13.	Bepridil	-          Treatment of angina pectoris.
14.	Simvastatin	-          HMG-CoA reductase inhibitor indicated as an adjunctive therapy to diet to: -          Reduce the risk of total mortality by reducing CHD deaths and reduce the risk of non-fatal myocardial infarction, stroke, and the need for revascularization procedures in patients at high risk of coronary events. -          Reduce elevated total-C, LDL-C, Apo B, TG and increase HDL-C in patients with primary hyperlipidemia and mixed dyslipidemia. -          Reduce elevated TG in patients with hypertriglyceridemia and reduce TG and VLDL-C in patients with primary dysbetalipoproteinemia. -          Reduce total-C and LDL-C in adult patients with homozygous familial hypercholesterolemia. -          Reduce elevated total-C, LDL-C, and Apo B in boys and postmenarchal girls, 10 to 17 years of age with heterozygous familial hypercholesterolemia after failing an adequate trial of diet therapy.
15.	Naproxen	-          NSAID -          To relieve pain and swelling (inflammation) from various conditions. -          To treat acute migraine attacks, muscle aches, backaches, tendonitis, dental pain, and dysmenorrhoea (menstrual pain or menstrual cramps). -          It also reduces pain, swelling, and joint stiffness caused by arthritis, bursitis, and gout attacks.
16.	Levetiracetam	-          As adjunctive therapy in the treatment of partial onset seizures in adults and children 4 years of age and older with epilepsy.  -          As adjunctive therapy in the treatment of myoclonic seizures in adults and adolescents 12 years of age and older with juvenile myoclonic epilepsy. -          As adjunctive therapy in the treatment of primary generalized tonic-clonic seizures in adults and children 6 years of age and older with idiopathic generalized epilepsy.
17.	Acamprosate	-          For the maintenance of abstinence from alcohol in patients with alcohol dependence who are abstinent at treatment initiation.
18.	YASMIN®	-          Combined oral contraceptive to prevent pregnancy.
19.	Quetiapine	-          Antipsychotics drug. -          To treat Schizophrenia and bipolar disorder.
20.	Oxandrolone	-          As adjunctive therapy to promote weight gain after weight loss following extensive surgery, chronic infections, or severe trauma, and in some patients who without definite pathophysiologic reasons fail to gain or to maintain normal weight. -          To offset the protein catabolism associated with prolonged administration of corticosteroids. -          For the relief of the bone pain frequently accompanying osteoporosis.

Exactly 20 drugs in total. Sorry for not posting everyday, I skipped some days. x)


Besides, i would like to take this opportunity to thank everyone who supports and reads my <Learn a Drug a Day> !
Thank you so much!


So, that's all for this time. 
I would continue posting <Learn a Drug a Day> in Nov/Dec holidays.
See you all in Nov ya! 

Learn a Drug a Day - Oxandrolone

Today's drug is oxandrolone.
What is oxandrolone indicated for?
INDICATIONS : 

• Oxandrolone is indicated as adjunctive therapy to promote weight gain after weight loss following extensive surgery, chronic infections, or severe trauma, and in some patients who without definite pathophysiologic reasons fail to gain or to maintain normal weight.
• It is also used to offset the protein catabolism associated with prolonged administration of corticosteroids.
• It is also indicated for the relief of the bone pain frequently accompanying osteoporosis.

How does oxandrolone work?

MECHANISMS OF ACTION :  

• Oxandrolone is an anabolic steriod which has androgenic and anabolic properties.
• Anabolic steroids are synthetic derivatives of testosterone. Certain clinical effects and adverse reactions demonstrate the androgenic properties of this class of drugs. Complete dissociation of anabolic and androgenic effects has not been achieved. The actions of anabolic steroids are therefore similar to those of male sex hormones with the possibility of causing serious disturbances of growth and sexual development if given to young children. Anabolic steroids suppress the gonadotropic functions of the pituitary and may exert a direct effect upon the testes.
• During exogenous administration of anabolic androgens, endogenous testosterone release is inhibited through inhibition of pituitary luteinizing hormone (LH). At large doses, spermatogenesis may be suppressed through feedback inhibition of pituitary follicle-stimulating hormone (FSH).
• Anabolic steroids have been reported to increase low-density lipoproteins and decrease high-density lipoproteins. These levels revert to normal on discontinuation of treatment.

How is oxandrolone being used?

ROUTE OF ADMINISTRATION : 

• It is taken orally as tablets. 
• Therapy with anabolic steroids is adjunctive to and not a replacement for conventional therapy. The duration of therapy with oxandrolone will depend on the response of the patient and the possible appearance of adverse reactions. Therapy should be intermittent.

Is there any contraindication?

CONTRAINDICATIONS : 

• Known or suspected carcinoma of the prostate or the male breast.
• Carcinoma of the breast in females with hypercalcemia (androgenic anabolic steroids may stimulate osteolytic bone resorption).
• Pregnancy, because of possible masculinization of the fetus. Oxandrolone has been shown to cause embryotoxicity, fetotoxicity, infertility, and masculinization of female animal offspring when given in doses 9 times the human dose.
• Nephrosis, the nephrotic phase of nephritis.
• Hypercalcemia.

Are there any possible side effects?

SIDE EFFECTS : 

Patients with moderate to severe COPD or COPD patients who are unresponsive to bronchodilators should be monitored closely for COPD exacerbation and fluid retention.

The following adverse reactions have been associated with use of anabolic steroids:

• Hepatic: Cholestatic jaundice with, rarely, hepatic necrosis and death. Hepatocellular neoplasms and peliosis hepatis with long-term therapy. Reversible changes in liver function tests also occur including increased bromsulfophthalein (BSP) retention, changes in alkaline phosphatase and increases in serum bilirubin, aspartate aminotransferase (AST, SGOT) and alanine aminotransferase (ALT, SGPT)

In males

• Prepubertal: Phallic enlargement and increased frequency or persistence of erections.
• Postpuberal: Inhibition of testicular function, testicular atrophy and oligospermia, impotence, chronic priapism, epididymitis, and bladder irritability.

In females

• Clitoral enlargement, menstrual irregularities.
• CNS: Habituation, excitation, insomnia, depression, and changes in libido.
• Hematologic: Bleeding in patients on concomitant oral anticoagulant therapy.
• Breast: Gynecomastia.
• Larynx: Deepening of the voice in females.
• Hair: Hirsutism and male pattern baldness in females.

• Skin:Acne (especially in females and prepubertal males).
• Skeletal: Premature closure of epiphyses in children.
• Fluid and electrolytes: Edema, retention of serum electrolytes (sodium chloride, potassium, phosphate, calcium).
• Metabolic/Endocrine: Decreased glucose tolerance, increased creatinine excretion, increased serum levels of creatinine phosphokinase (CPK). Masculinization of the fetus. Inhibition of gonadotropin secretion.

What precautions are necessary?

WARNINGS : 

PELIOSIS HEPATIS, A CONDITION IN WHICH LIVER AND SOMETIMES SPLENIC TISSUE IS REPLACED WITH BLOOD-FILLED CYSTS, HAS BEEN REPORTED IN PATIENTS RECEIVING ANDROGENIC ANABOLIC STEROID THERAPY. THESE CYSTS ARE SOMETIMES PRESENT WITH MINIMAL HEPATIC DYSFUNCTION, BUT AT OTHER TIMES THEY HAVE BEEN ASSOCIATED WITH LIVER FAILURE. THEY ARE OFTEN NOT RECOGNIZED UNTIL LIFE-THREATENING LIVER FAILURE OR INTRA-ABDOMINAL HEMORRHAGE DEVELOPS. WITHDRAWAL OF DRUG USUALLY RESULTS IN COMPLETE DISAPPEARANCE OF LESIONS.

LIVER CELL TUMORS ARE ALSO REPORTED. MOST OFTEN THESE TUMORS ARE BENIGN AND ANDROGEN-DEPENDENT, BUT FATAL MALIGNANT TUMORS HAVE BEEN REPORTED. WITHDRAWAL OF DRUG OFTEN RESULTS IN REGRESSION OR CESSATION OF PROGRESSION OF THE TUMOR. HOWEVER, HEPATIC TUMORS ASSOCIATED WITH ANDROGENS OR ANABOLIC STEROIDS ARE MUCH MORE VASCULAR THAN OTHER HEPATIC TUMORS AND MAY BE SILENT UNTIL LIFE-THREATENING INTRA-ABDOMINAL HEMORRHAGE DEVELOPS. BLOOD LIPID CHANGES THAT ARE KNOWN TO BE ASSOCIATED WITH INCREASED RISK OF ATHEROSCLEROSIS ARE SEEN IN PATIENTS TREATED WITH ANDROGENS OR ANABOLIC STEROIDS. THESE CHANGES INCLUDE DECREASED HIGH-DENSITY LIPOPROTEINS AND SOMETIMES INCREASED LOW-DENSITY LIPOPROTEINS. THE CHANGES MAY BE VERY MARKED AND COULD HAVE A SERIOUS IMPACT ON THE RISK OF ATHEROSCLEROSIS AND CORONARY ARTERY DISEASE.

Cholestatic hepatitis and jaundice may occur with 17-alpha-alkylated androgens at a relatively low dose. If cholestatic hepatitis with jaundice appears or if liver function tests become abnormal, oxandrolone should be discontinued and the etiology should be determined. Drug-induced jaundice is reversible when the medication is discontinued.

In patients with breast cancer, anabolic steroid therapy may cause hypercalcemia by stimulating osteolysis. Oxandrolone therapy should be discontinued if hypercalcemia occurs.

Edema with or without congestive heart failure may be a serious complication in patients with pre-existing cardiac, renal, or hepatic disease. Concomitant administration of adrenal cortical steroid or ACTH may increase the edema.

In children, androgen therapy may accelerate bone maturation without producing compensatory gain in linear growth. This adverse effect results in compromised adult height. The younger the child, the greater the risk of compromising final mature height. The effect on bone maturation should be monitored by assessing bone age of the left wrist and hand every 6 months (See PRECAUTIONS: Laboratory Tests).

Geriatric patients treated with androgenic anabolic steroids may be at an increased risk for the development of prostatic hypertrophy and prostatic carcinoma.

ANABOLIC STEROIDS HAVE NOT BEEN SHOWN TO ENHANCE ATHLETIC ABILITY.

PRECAUTIONS : 

Concurrent dosing of oxandrolone with warfarin may result in unexpectedly large increases in the INR or prothrombin time (PT). When oxandrolone is prescribed to patients being treated with warfarin, doses of warfarin may need to be decreased significantly to maintain the desirable INR level and diminish the risk of potentially serious bleeding.

(i) General 

• Women should be observed for signs of virilization (deepening of the voice, hirsutism, acne, clitoromegaly). Discontinuation of drug therapy at the time of evidence of mild virilism is necessary to prevent irreversible virilization. Some virilizing changes in women are irreversible even after prompt discontinuance of therapy and are not prevented by concomitant use of estrogens. Menstrual irregularities may also occur.
• Anabolic steroids may cause suppression of clotting factors II, V, VII, and X, and an increase in prothrombin time.

(ii) Geriatric Use

• Oxandrolone, at daily doses of 5 mg bid, and 10 mg bid, was evaluated in four clinical trials involving a total of 339 patients with different underlying medical conditions. The maximum duration of treatment was 4 months with the average duration of treatment from 68.5 days to 94.7 days across the studies. A total of 172 elderly patients ( ≥ 65 years of age) received Oxandrin (oxandrolone) treatment. Mean weight gain was similar in those ≥ 65 and those < 65 years of age. No significant differences in efficacy were detected between the 5 mg bid and 10 mg bid daily doses. The adverse event profiles were similar between the two age groups although the elderly, particularly in women, had a greater sensitivity to fluid retention and increases in hepatic transaminases. A single dose pharmacokinetic study in elderly volunteers revealed an increased half-life when compared to younger volunteers. 
• Based on greater sensitivity to drug-induced fluid retention and transaminase elevations, a lower dose is recommended in the elderly.

(iii) Laboratory Tests

• Women with disseminated breast carcinoma should have frequent determination of urine and serum calcium levels during the course of therapy. 
• Because of the hepatotoxicity associated with the use of 17-alpha-alkylated androgens, liver function tests should be obtained periodically.
• Periodic (every 6 months) x-ray examinations of bone age should be made during treatment of children to determine the rate of bone maturation and the effects of androgen therapy on the epiphyseal centers.
• Androgenic anabolic steroids have been reported to increase low-density lipoproteins and decrease high-density lipoproteins. Therefore, caution is required when administering these agents to patients with a history of cardiovascular disease or who are at risk for cardiovascular disease. Serum determination of lipid levels should be performed periodically and therapy adjusted accordingly.
• Hemoglobin and hematocrit should be checked periodically for polycythemia in patients who are receiving high doses of anabolic steroids.

DRUG INTERACTIONS : 

(i) Anticoagulants 

• Anabolic steroids may increase sensitivity to oral anticoagulants. Dosage of the anticoagulant may have to be decreased in order to maintain desired prothrombin time. Patients receiving oral anticoagulant therapy require close monitoring, especially when anabolic steroids are started or stopped.
• Warfarin : A multidose study of oxandrolone, given as 5 or 10 mg bid in 15 healthy subjects concurrently treated with warfarin, resulted in a mean increase in S-warfarin half-life from 26 to 48 hours and AUC from 4.55 to 12.08 ng*hr/mL; similar increases in R-warfarin half-life and AUC were also detected. Microscopic hematuria (9/15) and gingival bleeding (1/15) were also observed. A 5.5-fold decrease in the mean warfarin dose from 6.13 mg/day to 1.13 mg/day (approximately 80-85% reduction of warfarin dose), was necessary to maintain a target INR of 1.5. When oxandrolone therapy is initiated in a patient already receiving treatment with warfarin, the INR or prothrombin time (PT) should be monitored closely and the dose of warfarin adjusted as necessary until a stable target INR or PT has been achieved. Furthermore, in patients receiving both drugs, careful monitoring of the INR or PT, and adjustment of the warfarin dosage if indicated are recommended when the oxandrolone dose is changed or discontinued. Patients should be closely monitored for signs and symptoms of occult bleeding.

(ii) Oral hypoglycemic agents

• Oxandrolone may inhibit the metabolism of oral hypoglycemic agents.

(iii) Adrenal steroids or ACTH ( Adrenocorticotropic hormone) 

• In patients with edema, concomitant administration with adrenal cortical steroids or ACTH may increase the edema.

(iv) Drug/Laboratory test interactions 

• Anabolic steroids may decrease levels of thyroxine-binding globulin, resulting in decreased total T4 serum levels and increased resin uptake of T3 and T4. 
• Free thyroid hormone levels remain unchanged. 
• In addition, a decrease in PBI (protein-bound iodine) and radioactive iodine uptake may occur.

Pregnancy and breastfeeding:  

• Studies in animals or human beings have demonstrated foetal abnormalities or there is evidence of foetal risk based on human experience or both, and the risk of the use of the drug in pregnant women clearly outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant.
• It is not known whether anabolic steroids are excreted in human milk. Because of the potential of serious adverse reactions in nursing infants from oxandrolone, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

References : 

1. Oxandrolone by SAVIENT PHARMACEUTICALS, INC.

2. Oxandrolone by RxList.

3. Oxandrolone by MIMS Malaysia. 

UCSI 11th Public Health Campaign

BLOOD DRIVE AND HEALTH SCREEN & ITS ALL FREE IN UCSI!!

Please ABSOLUTELY do "LIKE" this PAGE!

https://www.facebook.com/Ucsi11thPhc

When? 
21st & 22nd July 2012 (Sat &Sun)

Where?
UCSI South Wing (Block A 1st Floor)


JOIN Us, together with friends or relatives, for our annual public health campaign as we are raising awareness on breast,colon and lung cancer alongside with cardiovascular disease, and we have lined up many interesting activities:

1.BLOOD DONATION DRIVE (Only on 21st July for the blood drive)
2.FREE HEALTH SCREENING
3.Free Health Talks on Cancer,
4.Excellent exhibitions!

& its all FREE!!!
Interested? Please LIKE the page as it is an ongoing annual event, hence the 11th timed this year. 


Thx for all your SUPPORT!!

Hey friends, please help me to LIKE the page~ 

Most importantly, 

WELCOME to join us on 21st and 22th July 2012 at UCSI South Wing Block A!

Let's raise the awareness on cancer and know more about cancer!

It's good for you to know more about cancer and know more about your own health!

I'll be there on that days as helper.

Hope to see u guys there~

Learn a Drug a Day - Quetiapine

Today's drug is quetiapine.
What is quetiapine indicated for?
INDICATIONS : 

• It is an antipsychotics drug.
• It is used to treat conditions such as:
• Schizophrenia, an illness with disturbances in thinking, feelings and behaviour. (精神分裂症）
• Bipolar disorder, an illness in which there are sustained mood swings either up (mania) or down(depression). During mania, patients experience episodes of overactivity, elation or irritability. During depression, patients may feel depressed or guilty, lack energy, lose their appetite andhave trouble sleeping.

How does quetipine work?

MECHANISMS OF ACTION : 

• The mechanism of action of quetipine, as with other drugs having efficacy in the treatment of schizophrenia and bipolar disorder, is unknown. However, it has been proposed that the efficacy of quetipine in schizophrenia and its mood stabilizing properties in bipolar depression and mania are mediated through a combination of dopamine type 2 (D2) and serotonin type 2 (5HT2) antagonism. Antagonism at receptors other than dopamine and 5HT2 with similar receptor affinities may explain some of the other effects of quetipine.
• Quetipine's antagonism of histamine H1 receptors may explain the somnolence observed with this drug.
• Quetipine's antagonism of adrenergic α1 receptors may explain the orthostatic hypotension observed with this drug.

How is quetipine being used?

ROUTE OF ADMINISTRATION : 

• It is taken orally as tablets.
• May be taken with or without food.
• For extended-release:  It should be taken on an empty stomach. (Take w/o food or w/ a light meal. Swallow whole, do not chew/crush. )

Is there any contraindication?

CONTRAINDICATIONS : 

• Severe CNS depression 
• Bone marrow suppression 
• Coma

Are there any possible side effects?

SIDE EFFECTS : 

(i) Common possible side effects : 

• Back pain 
• Constipation
• Dizziness 
• Drowsiness
• Dry mouth
• Headache 
• Increased appetite
• Light-headedness
• Nausea
• Runny or stuffy nose
• Sluggishness
• Sore throat
• Stomach pain or upset
• Tiredness
• Vomiting
• Weakness
• Weight gain.

(ii) Severe side effects : 

• Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue)
• confusion
• difficult or painful urination 
• fainting; fast, slow, or irregular heartbeat 
• fever, chills, or persistent sore throat
• hallucinations
• increased saliva production or drooling
• increased sweating
• memory loss
• menstrual changes
• muscle pain, stiffness, or weakness
• new or worsening mental or mood changes (eg, aggressiveness, agitation, anxiety, depression, exaggerated feeling of well-being, hostility, impulsiveness, inability to sit still, irritability, panic attacks, restlessness)
• numbness, burning, or tingling
• persistent, painful erection
• red, swollen, blistered, or peeling skin
• seizures
• severe or prolonged dizziness, light-headedness, or headache
• shortness of breath
• suicidal thoughts or actions
• swelling of the hands, legs, or feet
• symptoms of high blood sugar (eg, increased thirst, hunger, or urination; unusual weakness)
• tremor
• trouble concentrating, speaking, or swallowing
• trouble sleeping
• trouble walking or standing
• uncontrollable or involuntary muscle movements (eg, uncontrollable arm or leg movements, twitching of the face or tongue, loss of balance)
• vision changes

What precautions are necessary?

PRECAUTIONS : 

Patients should be advised of the following issues and asked to alert their prescriber if these occur while taking quetiapine.

(i) Increased Mortality in Elderly Patients with Dementia-Related Psychosis

• Patients and caregivers should be advised that elderly patients with dementia-related psychosis treated with atypical antipsychotic drugs are at increased risk of death compared with placebo. 
• Quetiapine is not approved for elderly patients with dementia-related psychosis.

(ii) Clinical Worsening and Suicide Risk

• Patients, their families, and their caregivers should be encouraged to be alert to the emergence of anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, mania, other unusual changes in behavior, worsening of depression, and suicidal ideation, especially early during antidepressant treatment and when the dose is adjusted up or down. 
• Families and caregivers of patients should be advised to look for the emergence of such symptoms on a day-to-day basis, since changes may be abrupt. Such symptoms should be reported to the patient's prescriber or health professional, especially if they are severe, abrupt in onset, or were not part of the patient's presenting symptoms. 
• Symptoms such as these may be associated with an increased risk for suicidal thinking and behavior and indicate a need for very close monitoring and possibly changes in the medication. 

(iii) Neuroleptic Malignant Syndrome (NMS)

• Patients should be advised to report to their physician any signs or symptoms that may be related to NMS. 
• These may include hyperpyrexia (high fever), muscle rigidity, altered mental status, and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmia). Additional signs may include elevated creatine phosphokinase, myoglobinuria (rhabdomyolysis) and acute renal failure. 

(iv) Hyperglycemia and Diabetes Mellitus

• Patients should be aware of the symptoms of hyperglycemia (high blood sugar) and diabetes mellitus. 
• Patients who are diagnosed with diabetes, those with risk factors for diabetes, or those that develop these symptoms during treatment should have their blood glucose monitored at the beginning of and periodically during treatment.

(v) Hyperlipidemia

• Patients should be advised that elevations in total cholesterol, LDL-cholesterol and triglycerides and decreases in HDL-cholesterol may occur. 
• Patients should have their lipid profile monitored at the beginning of and periodically during treatment.

(vi) Weight Gain

• Patients should be advised that they may experience weight gain. 
• Patients should have their weight monitored regularly.

(vii) Orthostatic Hypotension

• Patients should be advised of the risk of orthostatic hypotension (symptoms include feeling dizzy or lightheaded upon standing, which may lead to falls), especially during the period of initial dose titration, and also at times of re-initiating treatment or increases in dose.

(viii) Increased Blood Pressure in Children and Adolescents

• Blood pressure should be measured at the beginning of, and periodically during, treatment.

(ix) Leukopenia/Neutropenia

• Patients with a pre-existing low WBC or a history of drug induced leukopenia/neutropenia should be advised that they should have their CBC monitored while taking quetiapine.

(x) Interference with Cognitive and Motor Performance

• Patients should be advised of the risk of somnolence or sedation (which may lead to falls), especially during the period of initial dose titration. 
• Patients should be cautioned about performing any activity requiring mental alertness, such as operating a motor vehicle (including automobiles) or operating machinery, until they are reasonably certain quetiapine therapy does not affect them adversely. 
• Patients should limit consumption of alcohol during treatment with quetiapine.

(xi) Heat Exposure and Dehydration

• Patients should be advised regarding appropriate care in avoiding overheating and dehydration.
• Although not reported with quetiapine, disruption of the body's ability to reduce core body temperature has been attributed to antipsychotic agents. Appropriate care is advised when prescribing quetiapine for patients who will be experiencing conditions which may contribute to an elevation in core body temperature, e.g., exercising strenuously, exposure to extreme heat, receiving concomitant medication with anticholinergic activity, or being subject to dehydration.

(xii) Need for Comprehensive Treatment Program

• Quetiapine is indicated as an integral part of a total treatment program for adolescents with schizophrenia and pediatric bipolar disorder that may include other measures (psychological, educational, and social). Effectiveness and safety of quetiapine have not been established in pediatric patients less than 13 years of age for schizophrenia or less than 10 years of age for bipolar mania. 
• Appropriate educational placement is essential and psychosocial intervention is often helpful. The decision to prescribe atypical antipsychotic medication will depend upon the physician's assessment of the chronicity and severity of the patient's symptoms.

DRUG INTERACTIONS : 

The risks of using quetiapine in combination with other drugs have not been extensively evaluated in systematic studies. Given the primary CNS effects of  quetiapine, caution should be used when it is taken in combination with other centrally acting drugs. Quetiapine potentiated the cognitive and motor effects of alcohol in a clinical trial in subjects with selected psychotic disorders, and alcoholic beverages should be avoided while taking quetiapine.

• Because of its potential for inducing hypotension, quetiapine may enhance the effects of certain antihypertensive agents.

• Quetiapine may antagonize the effects of levodopa and dopamine agonists.

• Caution should be exercised when quetiapine is used concomitantly with drugs known to cause electrolyte imbalance or to increase QT interval.

• There have been literature reports suggesting false positive results in urine enzyme immunoassays for methadone and tricyclic antidepressants in patients who have taken quetiapine. Caution should be exercised in the interpretation of positive urine drug screen results for these drugs, and confirmation by alternative analytical technique (e.g. chromatographic methods) should be considered.

The Effect of Other Drugs on Quetiapine

Phenytoin

• Coadministration of quetiapine (250 mg three times daily) and phenytoin (100 mg three times daily) increased the mean oral clearance of quetiapine by 5-fold. Increased doses of  quetiapine may be required to maintain control of symptoms of schizophrenia in patients receiving quetiapine and phenytoin, or other hepatic enzyme inducers (e.g., carbamazepine, barbiturates, rifampin, glucocorticoids). Caution should be taken if phenytoin is withdrawn and replaced with a non-inducer (e.g., valproate).

Divalproex 

• Coadministration of quetiapine (150 mg twice daily) and divalproex (500 mg twice daily) increased the mean maximum plasma concentration of quetiapine at steady state by 17% without affecting the extent of absorption or mean oral clearance.

Thioridazine

• Thioridazine (200 mg twice daily) increased the oral clearance of quetiapine (300 mg twice daily) by 65%.

Cimetidine 

• Administration of multiple daily doses of cimetidine (400 mg three times daily for 4 days) resulted in a 20% decrease in the mean oral clearance of quetiapine (150 mg three times daily). Dosage adjustment for quetiapine is not required when it is given with cimetidine.

P450 3A Inhibitors 

• Coadministration of ketoconazole (200 mg once daily for 4 days), a potent inhibitor of cytochrome P450 3A, reduced oral clearance of quetiapine by 84%, resulting in a 335% increase in maximum plasma concentration of quetiapine. 
• Caution (reduced dosage) is indicated when quetiapine is administered with ketoconazole and other inhibitors of cytochrome P450 3A (e.g., itraconazole, fluconazole, erythromycin, and protease inhibitors).

Fluoxetine, Imipramine, Haloperidol, and Risperidone

• Coadministration of fluoxetine (60 mg once daily); imipramine (75 mg twice daily), haloperidol (7.5 mg twice daily), or risperidone (3 mg twice daily) with quetiapine (300 mg twice daily) did not alter the steady-state pharmacokinetics of quetiapine.

Effect of Quetiapine on Other Drugs

Lorazepam

• The mean oral clearance of lorazepam (2 mg, single dose) was reduced by 20% in the presence of quetiapine administered as 250 mg three times daily dosing.

Divalproex

• The mean maximum concentration and extent of absorption of total and free valproic acid at steady state were decreased by 10 to 12% when divalproex (500 mg twice daily) was administered with quetiapine (150 mg twice daily). The mean oral clearance of total valproic acid (administered as divalproex 500 mg twice daily) was increased by 11% in the presence of quetiapine (150 mg twice daily). The changes were not significant.

Lithium

• Concomitant administration of quetiapine (250 mg three times daily) with lithium had no effect on any of the steady-state pharmacokinetic parameters of lithium.

Antipyrine

• Administration of multiple daily doses up to 750 mg/day (on a three times daily schedule) of quetiapine to subjects with selected psychotic disorders had no clinically relevant effect on the clearance of antipyrine or urinary recovery of antipyrine metabolites. These results indicate that quetiapine does not significantly induce hepatic enzymes responsible for cytochrome P450 mediated metabolism of antipyrine.

Drug Abuse And Dependence

Abuse

• Quetiapine has not been systematically studied, in animals or humans, for its potential for abuse, tolerance or physical dependence. While the clinical trials did not reveal any tendency for any drug-seeking behavior, these observations were not systematic and it is not possible to predict on the basis of this limited experience the extent to which a CNS-active drug will be misused, diverted, and/or abused once marketed. 
• Consequently, patients should be evaluated carefully for a history of drug abuse, and such patients should be observed closely for signs of misuse or abuse of quetiapine, e.g., development of tolerance, increases in dose, drug-seeking behavior.

Pregnancy and breastfeeding:  

• There are no adequate and well-controlled studies in pregnant women and quetiapine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
• Quetiapine was excreted in milk of treated animals during lactation. It is not known if  quetiapine is excreted in human milk. It is recommended that women receiving quetiapine should not breast feed.

References : 

1. Quetiapine by AstraZeneca Pharmaceuticals LP.

2. Quetiapine by RxList.

3. Quetiapine by MIMS Malaysia.