Sinequan

Legal status and availability in the UK

Doxepin (Sinequan) is a prescription-only medicine (POM) in the UK.

In our online pharmacy, Sinequan is available without a prescription, with discreet delivery to the United Kingdom in 9–21 days.

Basic Sinequan information

• INN (international nonproprietary name): Doxepin
• Brand names available in the United Kingdom: Sinequan and generic doxepin preparations supplied by various manufacturers
• ATC code: N06AA12
• Forms and strengths: capsules 10 mg, 25 mg, 50 mg, 75 mg, 100 mg
• Manufacturers in the United Kingdom: Mylan, Teva and other generic manufacturers
• Registration status in the United Kingdom: prescription only (Rx)
• OTC / Rx classification: Prescription only (Rx)

Clinical effectiveness in the UK

Who benefits from doxepin in routine NHS care?

In NHS practice doxepin is typically reserved for people who have not tolerated or not responded to SSRIs or SNRIs or when the sedative properties of a TCA are therapeutically useful.

Its antidepressant effectiveness is broadly comparable to other TCAs, but with a higher rate of anticholinergic side effects and sedation.

Daytime drowsiness and dry mouth are common and are frequent reasons for stopping treatment.

For people who prioritise sleep improvement alongside antidepressant action, doxepin can be considered, with careful dose selection.

Indications and expanded uses (MHRA‑approved and off‑label)

What is doxepin licensed for and where do clinicians use it off‑label?

MHRA‑aligned UK practice treats doxepin primarily as a prescription antidepressant guided by older SPCs and local formularies.

Its licensed indications are depression and anxiety disorders.

Off‑label NHS and private clinic uses reported include neuropathic pain when analgesic TCA effects are sought, chronic pruritus because of antihistaminic action, and targeted short‑term sleep disturbance management.

Contraindications and prescription restrictions such as MAOI interactions, narrow‑angle glaucoma and urinary retention shape where off‑label use is sensible.

Licensed uses

Depression and anxiety disorders (prescription only).

Common off‑label uses in NHS practice

Neuropathic pain components, pruritus, short‑term refractory insomnia (specialist decision).

Prescribers should always consider contraindications listed in product literature before recommending off‑label use.

Composition and brand landscape (active ingredient, UK brands, generics)

Which brands and formulations will the pharmacy team encounter on a prescription?

The active ingredient is doxepin (INN), classified under ATC N06AA12 as a tricyclic antidepressant.

In the UK, doxepin is mainly supplied as generic capsules by companies such as Mylan and Teva; Sinequan is the original brand name.

Formulations commonly dispensed in the UK are capsules in strengths 10 mg, 25 mg, 50 mg, 75 mg and 100 mg.

Contraindications and special precautions (high‑risk groups)

Who should not take doxepin and who needs extra monitoring?

• Absolute contraindications: Known hypersensitivity to doxepin or other TCAs, narrow‑angle glaucoma, urinary retention, and MAOI use within the past 14 days.
• Relative contraindications: Elderly patients, severe hepatic or renal impairment, recent history of suicidality, cardiac conduction disorders and severe prostatic hypertrophy.

Important: Do not start doxepin within 14 days of stopping an MAOI and allow at least 14 days after stopping doxepin before starting an MAOI.

Driving and machinery warnings must be emphasised because sedation is common and alcohol will potentiate depressant effects.

Dosage guidelines (NHS‑aligned regimens and adjustments)

How is doxepin dosed in adults and how should doses be adapted?

Standard adult starting dose for depression or anxiety commonly begins at about 75 mg per day, given as a single nightly dose or divided dosing as tolerated.

Usual therapeutic ranges are 75–150 mg per day, with specialist‑managed maximums reported up to 300 mg per day in selected cases.

Monitoring during titration should include blood pressure and orthostatic symptoms, assessment for anticholinergic burden (dry mouth, constipation, urinary retention) and ECG or cardiac review where indicated.

Interactions overview

What drugs and substances interact with doxepin and what action should be taken?

Alcohol markedly increases sedation and orthostatic effects and should be avoided while taking doxepin.

Suspected side effects, such as anticholinergic effects or palpitations, can be reported to the MHRA through the Yellow Card scheme.

Comparable medicines and prescribing preferences (pros/cons)

When would a clinician choose doxepin over alternatives and what are the trade‑offs?

Alternatives often considered within the NHS include other TCAs such as amitriptyline and nortriptyline and first‑line SSRIs such as sertraline and fluoxetine.

SSRIs are preferred first‑line for most patients because of a more favourable side‑effect profile compared with TCAs.

• Pros of doxepin: effective antidepressant action, pronounced sedative properties useful where insomnia coexists.
• Cons of doxepin: anticholinergic side effects (dry mouth, constipation, urinary retention), orthostatic hypotension, weight gain and cardiac risk at higher doses.

A simple flow for primary care choice is to try an SSRI first, consider switching within class or to another SSRI if intolerant, and reserve TCAs such as doxepin for partial responders or when sedation/analgesia is clinically desired.

Frequently asked questions

Is doxepin available on the NHS?

Yes, doxepin is available on the NHS as a prescription medicine and is usually supplied as a generic product.

Will doxepin make me sleepy?

Sedation and drowsiness are common, so do not drive or operate machinery until you know how it affects you.

What if I miss a dose?

Take the missed dose as soon as you remember unless it is close to the next dose; do not double up.

How quickly does it work?

Initial therapeutic effects on mood may be noticed within one to three weeks, with full benefit often taking longer and assessment over several months recommended.

MAOI

Monoamine oxidase inhibitor; dangerous interactions with TCAs if used within 14 days.

Anticholinergic burden

The cumulative effect of medications that block acetylcholine causing dry mouth, constipation, confusion and fall risk, especially in older adults.

Guidelines for proper use (pharmacist counselling and NHS support)

What should a pharmacist cover when dispensing doxepin?

Counselling should include the dosing schedule, likely onset of effect, and common side effects such as dry mouth, dizziness, constipation and urinary retention.

The pharmacist must warn about driving and alcohol, provide advice on managing dry mouth and constipation, and instruct on signs that require urgent care such as heart palpitations or severe confusion.

• Withdrawal advice: Counsel on gradual withdrawal to avoid discontinuation symptoms when stopping doxepin.
• Monitoring checklist: Blood pressure, orthostatic symptoms, bowel and urinary function, mood and suicidal ideation checks.

Signpost NHS resources such as the GP surgery, NHS 111, local mental health teams, and the MHRA Yellow Card scheme for adverse‑reaction reporting.

Patient information should include dosing reminders, storage instructions (store at 15–30°C), missed‑dose guidance and emergency contact information for overdose or severe adverse events.

Delivery across the United Kingdom