Dosulepin

Oral
Depression

Contraindicated.

May be taken with or without food.

Manic phase of bipolar disorder, arrhythmias, heart block, immediate recovery period after MI. Hepatic impairment. Concomitant admin w/ MAOIs or w/in 14 days after discontinuation.

Patient w/ history of bipolar disorder and psychosis. Patient w/ severe CV disease including heart failure, conduction disorders or cardiac arrhythmia; risk factors for QTc prolongation/TdP including congenital long QT syndrome; significant risk of suicide; glaucoma, urinary retention, prostatic hypertrophy. Avoid abrupt withdrawal. Elderly. Pregnancy and lactation.

Drowsiness, dizziness, tremor, confusional states, paraesthesia, EEG patterns alterations, disorientation; dry mouth, urinary retention, sweating; hypotension, postural hypotension, tachycardia, arrhythmias (including ventricular tachycardia, ventricular fibrillation and torsades de pointes), conduction defects, palpitations; increased or decreased libido; constipation, nausea, vomiting; blurred vision. Rarely, dysarthria, extrapyramidal symptoms, paralytic ileus, tremor, neuroleptic malignant syndrome, precipitation of angle-closure glaucoma.

This drug may cause drowsiness, if affected do not drive or operate machinery.

Closely monitor for clinical worsening and suicidality (esp at the beginning of the treatment and dose change). Perform ECG prior to treatment. Monitor CV and ECG. Examine eyes regularly during prolonged treatment.

Symptoms: Dry mouth, blurred vision, paralytic ileus, mydriasis, urinary retention; agitation, ataxia, hyperpyrexia, delirium, convulsions, resp depression, coma, unconsciousness, muscle twitching, hyperreflexia, hypothermia, resp or metabolic alkalosis, visual hallucinations; cyanosis, shock, hypotension, tachycardia, cardiac arrhythmias (including torsades de pointes), QTc prolongation, conduction disorders, heart failure, rarely cardiac arrest. Management: Ensure a clear airway and adequate ventilation. Correct hypoxia and acid-based imbalance by assisted ventilation and IV Na bicarbonate, as needed. Admin activated charcoal w/in 2 hr prior to ingestion. Persist w/ prolonged CPR (at least an hr) for cardiac arrest. Admin of IV diazepam or lorazepam may control convulsions.

Increased risk of ventricular arrhythmias w/ drugs that prolong QT interval. May potentiate sedative effect w/ barbiturates, tranquilisers, CNS depressants. May block antihypertensive effect of guanethidine and other adrenergic neurone blocking drugs. May potentiate effects of anticholinergics, antihistamines, sympathomimetics. Increased risk of postural hypotension w/ diuretics. May antagonise effect of antiepileptics.
Potentially Fatal: Concomitant admin w/ MAOIs or w/in 14 days after discontinuation may cause cerebral excitation followed by coma or dangerous hyperthermia.

May potentiate effect of alcohol.

Description:
Mechanism of Action: Dosulepin hydrochloride (also known as dothiepin) is a TCA which inhibits norepinephrine and 5-hydroxytryptamine uptake from the nerve endings, thereby increases availability at central norepinephrine synapses. It has anticholinergic, antihistamine and central sedative properties.
Pharmacokinetics:
Absorption: Readily absorbed from the GI tract.
Distribution: Enters breast milk (low concentration). Plasma protein binding: Approx 84% (as unchanged drug).
Metabolism: Extensively demethylated by first-pass hepatic metabolism to its primary active metabolite, desmethyldothiepin (northiaden).
Excretion: Via urine (mainly as metabolites); faeces (small amounts). Elimination half-life: Approx 14-24 hr (dosulepin); 23-46 hr (metabolites).

Source: National Center for Biotechnology Information. PubChem Database. Dosulepin, CID=5284550, https://pubchem.ncbi.nlm.nih.gov/compound/Dosulepin (accessed on Jan. 21, 2020)

Store below 25°C.

Antidepressants

N06AA16 - dosulepin ; Belongs to the class of non-selective monoamine reuptake inhibitors. Used in the management of depression.

Anon. Dosulepin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 14/03/2016.

Buckingham R (ed). Dosulepin Hydrochloride. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 14/03/2016.

Joint Formulary Committee. Dosulepin Hydrochloride (Dothiepin Hydrochloride). British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 14/03/2016.

Mylan New Zealand Limited. Dopress Capsules 25 mg and Tablets 75 mg data sheet 8 April 2014. Medsafe. http://www.medsafe.govt.nz/. Accessed 14/03/2016.