Doxepin : Therapeutic uses, Clinical uses, Indications, Dosage, Side Effects, Warnings, Interactions, Precautions, Contraindications & Brand names
Doxepin is a first generation H1- receptor blocker (Anti-histamine) with significant H2- antagonist activity & a newer tricyclic antidepressant (TCAs) drug that inhibit norepinephrine & serotonin reuptake into the presynaptic neuron, & indicated for depression primarily.
Dose : 10-150 mg (Oral), 5% (Topical)
Route : Oral, Topical
Plasma Half-life : 8-24 hours
Duration of action : 6-24 hours
Bioavailability : ?
Chemical formula : C19H21NO
IUPAC name : (E/Z)-3-(dibenzo[b,e]oxepin-11(6H)-ylidene)-N,N-dimethylpropan-1-amine
Trade name : Spectra, Doxin, Doxetar, Sinequan, Noctaderm, Doxiderm, Patoderm, Adnor, Anten, Antidoxe, Apo-Doxepin, Colian, Dofu, Doneurin, Dospin, Doxal, Doxesom, Doxure, Expan, Flake, Gilex, Ichderm, Li Ke Ning, Mareen, Oxpin, Qualiquan, Quitaxon, Sagalon, Silenor, Sinequan, Sinquan
Therapeutic uses : Doxepin has following usage :
- Primarily indicated as anti-depressant drug for treating moderate to severe depression (Major/endogenous depression).
- Its low doses can be used to treat insomnia.
- Topical doxepin has been used to relieve itching in atopic dermatitis, lichen simplex, etc. because of its antipruritic action.
- May be effective in Obsessive-compulsive disorder OCD and phobic states.
- May reduce compulsive eating in bulimia, and help patients with body dysmorphic disorder, compulsive buying and kleptomania.
- It have marked property of sedation.
Note:- Among H1- antagonist, Doxepin is the only drug that is marketed as a tricyclic antidepressant.
Side effects : Doxepin also block α-adrenergic, and muscarinic receptors. Side effects are common with tricyclic antidepressants, thus, Doxepin may produce following side effects:
- Blurred vision,
- Xerostomia (dry mouth),
- Urinary retention,
- Sinus tachycardia,
- Constipation,
- Bad taste,
- Epigastric distress,
- Motor incoordination,
- Aggravation of angle-closure glaucoma,
- Prominent sedation,
- Orthostatic hypotension,
- Dizziness,
- Reflex tachycardia,
- Increased appetite,
- Weight gain,
- Diminished alertness and concentration,
- Sweating and fine tremors,
- Lowered seizure threshold ,
- Sexual dysfunction,
- May exacerbate certain medical conditions, such as benign prostatic hyperplasia, epilepsy, and preexisting arrhythmias.
- Acute overdose produces central excitation, tremors, hallucinations, muscular incordination, convulsions, flushing, hypotension, fever and some other features of belladonna poisoning. Death is due to respiratory and cardiovascular failure.
TCAs also have quinidine-like effects on cardiac conduction that can be life threatening with overdose and limit the use of TCAs in patients with coronary heart disease.
Drug Interactions : Doxepin may interact with following drugs :
Precautions
Before using this medication, tell your doctor or pharmacist
- If you are allergic to it; or if you have any other allergies.
- Your medical history, especially of respiratory problems, bleeding problems, glaucoma, heart problems, high bp, liver disease, seizures, GIT problems, hyperthyroidism, urinary problems, psychiatric disorders.
Contraindications
- TCAs (like all antidepressants) should be used with caution in patients with bipolar disorder, even during their depressed state, because antidepressants may cause a switch to manic behavior.
- Depressed patients who are suicidal should be given only limited quantities of these drugs and be monitored closely.
For detailed query or in case of uncertainty, Always consult your doctor or pharmacist.
