sinequan

How long does Doxepin Hydrochloride stay in your body?

The elimination half-life of doxepin hydrochloride is about 8 to 24 hours (average about 17 hours) — the time it takes the body to clear about half of it. As a rule of thumb, a medicine is mostly gone after roughly 4 to 5 half-lives, though this varies from person to person with age and kidney or liver function. The label's number is for doxepin itself. Its main active metabolite, nordoxepin (N-desmethyldoxepin), lasts far longer — a half-life of 33 to 80 hours (mean 51 hours) — so drug activity persists well beyond what the parent half-life suggests, and steady state takes days rather than hours. The low-dose insomnia tablet (Silenor 3 mg/6 mg) is not a different-duration product: its label gives a terminal half-life of 15.3 hours for doxepin and 31 hours for nordoxepin, essentially the same range. There is no extended-release oral doxepin. Neither label gives a separate half-life figure for older adults, but both warn that doxepin can cause confusion and oversedation in geriatric patients and that starting doses should be lower. Liver impairment matters more than kidney impairment: 55%–87% of an oral dose is cleared by first-pass hepatic metabolism, and the label states patients with hepatic impairment may have greater systemic exposure; renal impairment has not been studied, and because little drug leaves in the urine unchanged, the Silenor label says renal impairment would not be expected to change doxepin levels much. Exposure is also higher in CYP2C19 or CYP2D6 poor metabolizers and with inhibitors such as cimetidine, which roughly doubled doxepin Cmax and AUC.

This is general information, not medical advice. It doesn’t tell you when a drug test would read negative (tests detect substances for different, often longer, windows) or when it’s safe to take another dose — ask your pharmacist or prescriber. Source: Doxepin Hydrochloride Capsules — FDA Prescribing Information, Section 12.3 Pharmacokinetics (Mylan Pharmaceuticals, DailyMed, updated 2025-10-15).

Frequently asked questions

What does Sinequan treat?

Sinequan (Doxepin Hydrochloride) may be used to treat anxiety disorders, depressive disorder, atopic dermatitis, pain, pruritus, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.

How is Sinequan rated?

pharmaranks gives Sinequan a composite score of 3.2 out of 5, currently based on 1 weighted source (FDA regulatory recall-safety data weighted highest). See our methodology at /how-we-rate.

How much does Sinequan cost?

Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $4.84 for 30, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins. Pharmacies pay less for a same-class option, Imipramine Hydrochloride — about $2.54 on the same basis.

Is there a coupon or discount for Sinequan?

pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Sinequan. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.

Who makes Sinequan?

Sinequan is marketed by Pfizer. You can see Pfizer's full profile, rating, and other products on pharmaranks.

Is Sinequan a brand-name or generic drug?

Sinequan is a brand-name product with the active ingredient Doxepin Hydrochloride. Lower-cost generic equivalents containing Doxepin Hydrochloride are available — ask your pharmacist.

Is Sinequan available over the counter?

No. Sinequan is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.

What forms does Sinequan come in?

Sinequan is currently marketed as capsule, per the FDA's National Drug Code Directory.

What class of drug is Sinequan?

Sinequan is classified as tricyclic antidepressant, per the FDA's Established Pharmacologic Class.

Is Sinequan FDA-registered?

Sinequan is on record with the U.S. FDA under application number NDA016798. You can verify this on its official FDA label.

Has Sinequan been recalled by the FDA?

Sinequan has no FDA recalls recorded under its own application in the openFDA enforcement database. Its recall-safety score reflects its manufacturer's overall recall record. This is general reference, not medical advice — check the FDA recall database for the latest alerts.

Is Sinequan safe?

There's no single safe-or-not verdict. pharmaranks gives Sinequan a recall-safety score of 64/100, based on its FDA recall history (no recalls under its own FDA application) — not an efficacy or side-effect rating. Review its FDA-label side effects and warnings before use, and always consult a licensed professional.