Doxepin (doxepin) capsules 25 mg. №30

Description

Doxepin 25 mg. Storage
active substance: doxepin;

1 capsule contains doxepin 10 mg or 25 mg as doxepin hydrochloride;

Doxepin 25 mg. excipients: corn starch, lactose monohydrate, magnesium stearate, sodium lauryl sulfate;

capsule shell: indigo carmine (E 132), titanium dioxide (E 171), gelatin, erythrosine (E 127); for 10 mg capsules, a patented blue V (E 131) is added.

Doxepin 25 mg. Dosage form
Capsules.

Basic physical and chemical properties:

for capsules of 10 mg: body – blue, lid – cherry;

for capsules of 25 mg: body – pink, lid – cherry;

white powder in cylindrical capsules with rounded ends and size № 4.

Pharmacotherapeutic group
Antidepressants. Nonselective inhibitors of neuronal reuptake of monoamines. ATX code N06A A12.

Pharmacological properties
Pharmacodynamics. Doxepin belongs to a group of tricyclic antidepressants. Antidepressant action is combined with anxiolytic and sedative.

Doxepin inhibits the reuptake of biogenic amines (norepinephrine and serotonin) in synaptic structures, and also has antihistamine, cholinolytic and α1-adrenoblocking effects. Does not cause euphoria, psychomotor arousal.

Pharmacokinetics.

Doxepin is well absorbed from the digestive tract, quickly (2-4 hours after ingestion) reaches its maximum concentration in serum. Steady therapeutic concentration in the blood is reached approximately 2 weeks after the start of treatment.

Doxepin is metabolized in the liver mainly by demethylation to form the main active metabolite, desmethyldoxepin (nordoxepine). Plasma protein binding of doxepin and its metabolites is approximately 76%. The volume of distribution is approximately 20 l / kg. The half-life of doxepin is 8-24 hours, the main active metabolite – 33-80 hours. Doxepin crosses the placenta and the blood-brain barrier and passes into breast milk.

Indication
Neurotic disorders with symptoms of depression or anxiety.
Organic neuroses associated with insomnia.
Depressive and anxiety states in alcoholism.
Depression and anxiety associated with somatic disorders and diseases.
Depression accompanied by fear and anxiety in the context of psychosis, including involutional depression and the depressive phase of bipolar disorder.

Contraindication
Hypersensitivity to doxepin, tricyclic antidepressants or to any of the excipients;
manic state;
severe liver disorders;
breastfeeding period;
glaucoma;
tendency to urinary retention;
concomitant use with monoamine oxidase inhibitors (MAOIs) or the use of the latter for two weeks before starting doxepin therapy.
Interaction with other medicinal products and other forms of interaction
Metabolism of doxepin, as well as other tricyclic antidepressants, is carried out with the participation of isoenzymes of the cytochrome P450 system (CYP2D6). Concomitant use of inhibitors or substrates of these isoenzymes (quinidine, selective serotonin reuptake inhibitors) with doxepin may increase the concentration of tricyclic antidepressants in blood plasma.

The possibility of potentiation of the pharmacological effects of doxepin when co-administered with other antidepressants, alcohol or anxiolytics should be considered. Because it is known that MAO inhibitors may potentiate the effects of other medicinal products and associated adverse events, doxepin should not be used concomitantly with MAO inhibitors or within two weeks of the latter.

Cimetidine causes significant fluctuations in the equilibrium concentration of doxepin.

Doxepin should not be used concomitantly with sympathomimetics such as ephedrine, isoprenaline, norepinephrine, phenylephrine and phenylpropanolamine.

Analgesics for systemic and topical use containing sympathomimetics when used in combination with antidepressant therapy increase the risk of arrhythmia and hypotension or hypertension. If surgery is required, the anesthesiologist should be informed of the patient’s therapy.

Doxepin may reduce the effect of antihypertensive drugs such as debrisoquine, betanidine, guanethidine and clonidine. To prevent the effects of doxepin on the action of guanethidine, the dose of doxepin should not exceed 150 mg. It is recommended to monitor the patient’s condition with the simultaneous use of any antihypertensive drugs and tricyclic antidepressants.

Barbiturates may accelerate doxepin metabolism.

Doxepin may reduce the effectiveness of sublingual forms of nitrates.

Concomitant use of doxepin may require a reduction in the dose of thyroid hormones.