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Rx
AMWEL
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COMPOSITION
Amwel Tablet
Each Tab of Amwel contains :
Amitriptyline HCL 10mg /25mg
DESCRIPTION
Amwel
is a tricyclic anti-depressant drug (TCA). It is the most widely used TCA and
is an efficacious treatment for major depressive disorder (clinical
depression). Drug has marked sedative effect in comparison to imipramine &
is more suitable for depressed patients showing anxiety and agitation. Endogenous
depression responds to a greater than other types. It was originally developed by Merck and was initially approved by the United States Food and Drug
Administration (FDA) on 7 April 1961.
Chemical structure:
PHARMACODYNAMICS
Amwel produce anti-depressant effect by blocking
the neuronal uptake of noradrenaline & exert anti- cholinergic activity. It
also inhibit neuronal uptake of 5-HT and dopamine. The exact mechanism of
action is not known.
PHARMACOKINETICS
Absorption
Rapidly
absorbed.
Metabolism
Metabolized
in the liver by N-demethylation and bridge hydroxylation. Nortriptyline is an
intermediate active metabolite.
Elimination
50%
to 66% excreted in the urine within 24 hr. Excreted as glucuronide or sulfate
conjugate of metabolites. A small amount of unchanged drug excreted in the
urine. T ½ is 31 to 46 h.
Oncet of action:
Beneficial anti- depressant effect: 2-6 weeks.
Duration of action:
After prolonged therapy antidepressant effect may perist for upto 6 weeks.
Special Populations
Elderly
May
have increased plasma levels. Dosage adjustment may be necessary.
Indications
• Depressive illness accompanied by
anxiety, agitation, restlessness & sleep disturbances.
• Dysphoria and
depression in alcoholics.
• Masked
depression.
• Childhood
enurests (bed wetting)
• Chronic pain
• Peptic ulcer
• Bulimia
Dosage:
Adults : 10-25mg initially thrice daily increased by 10-25mg
every 2nd or 3rd day till optimal effect is obtained.
Max : 150-225 mg daily.
Patients over 6o years. 10mg thrice daily initially.
Alcoholics: 25mg 3-4 times daily.
Main dose ; 10-15 mg thrice daily.
Children : Not recommended in children less than 12 years.
Adverse Effect : Epigastric distress, sedation,
drowsiness, orthostatic hypotension, palpitation, dry mouth, urinary retention,
blurred vision, confusion, lowering of seizure threshold.
CONTRAINDICATIONS
Epilepsy, Narrow angle
glaucoma, serves heart diseases, severe liver impairment, retention of urine.
.
WARNING AND PRECAUTIONS
Special precautions
: Cardiac, hepatic or renal disease, not to drive or operate heavy machinery, hyperthyroidism,
activation of latent schizophrenia may occur, suicidal tendency in seriously
depressed patients.
Pregnancy :
Safely not established. Category D .
Lactation
: Use with caution. Excreted in breast milk.
Elderly & adolescents:
May be given in reduced dose.
General Advice
Give
drug with or immediately after food or fluid and in late afternoon or at
bedtime because of sedative effect. Tablets may be crushed.
DRUG INTERACTION
·
Anticholinergics: Enhanched effect of
anticholinergics may occur.
·
Barbiturates : serum level of imipramine
deceased, additive respiratory depressant effect.
·
Clonidine : Hypertensive crists.
·
Dicoumarol : Increase in anticoagulation
effects.
·
Disulfiram : Acute organic brain
syndrome.
·
Fluxoentine & Haloperidol :
Potentiate action of imipramine.
·
Levodopa: Its bioavailability is
reduced, hypertensive episodes.
·
MAOIs, Furazolidone: seizures, sweating,
coma, hyperexcitability, hyperthermia, tachycardia, Confusion, DIC
(Disseminated Intravascular Coagualation) and death.
·
Oral Contraceptives and phenothiazines :
Increase plasma level of amitriptyline.
·
Smokimg : Increase metabolic bio-
transformation.
Alchohol : Sedative effect of alcohol
potentiated