| Allergy symptoms, nausea/vomiting, motion sickness, and sedation (label; product-dependent). View labelExact | Dosing is indication-dependent (allergy vs nausea vs motion sickness vs sedation). Labels emphasize using the smallest dose adequate to relieve symptoms (label).
Sedation labeling includes bedtime dosing (e.g., 25–50 mg in adults, product-dependent). Next-day impairment can occur; avoid stacking with other sedatives when possible (label/class). | Sedating first-generation antihistamine (H1 antagonist) and phenothiazine derivative with anticholinergic/antiemetic properties; used for allergy symptoms, nausea, motion sickness, and sedation. | Hepatic | No | | - Sedation and next-day impairment (driving safety, falls risk).
- Respiratory depression risk when combined with other depressants or in sleep apnea.
- Anticholinergic effects (constipation, urinary retention, blurred vision) and delirium risk.
- Abnormal movements or rigidity/fever suggesting EPS or rare NMS.
| No | 2026-02-22 |
|---|
| Anxiety symptoms (label); pruritus; pre/postoperative sedation (label varies by product). View labelExact | Anxiety/acute distress (off label patterns vary): 25–50 mg every 6–8 hours as needed; consider 10–25 mg starting doses in older adults or high fall risk. | First-generation antihistamine (H1 antagonist) with sedating and anxiolytic effects; anticholinergic/antiemetic properties. | Hepatic | No | | - Sedation, falls, and driving impairment are often reassessed after initiation and during dose changes—especially in older adults.
- Anticholinergic effects (constipation, urinary retention, confusion) are commonly monitored; total anticholinergic burden is minimized when possible.
- QT risk: QT-prolonging co-medications and electrolytes are typically reviewed, and baseline ECGs are often considered when risk factors stack.
- If use becomes frequent, the diagnosis is often revisited and plans may shift toward long-term anxiety treatment rather than continued PRN escalation.
| No | 2025-12-28 |
|---|
| Allergy symptoms (OTC labeling varies). Off-label use is common for insomnia and acute anxiety-related distress (practice pattern). View labelExact | Allergy symptom dosing varies by product; one common pattern is 25–50 mg every 4–6 hours with a daily maximum (label varies). | First-generation antihistamine (H1 antagonist) with sedating and anticholinergic effects; commonly used OTC for allergies and as a sleep aid. | CYP2D6 | Single-dose mean 9 h | No | | - Sedation and next-day impairment (falls risk, driving safety).
- Anticholinergic effects (constipation, urinary retention, blurred vision).
- Confusion or delirium risk in older adults and polypharmacy (Beers).
- Duplicate diphenhydramine exposure from “PM” combination products.
| No | 2026-02-12 |
|---|
| OTC sleep aid (product-dependent). Also used in combination with pyridoxine for nausea/vomiting of pregnancy (label; product-dependent). View labelExact | OTC sleep aid labeling is product-dependent; one common direction is 25 mg once nightly about 30 minutes before bed. | First-generation antihistamine (H1 antagonist) with sedating and anticholinergic effects; OTC sleep aid and antiemetic ingredient (doxylamine/pyridoxine). | Hepatic | Single-dose mean 10 h; Single-dose range 10–15 h | No | | - Sedation and next-day impairment (falls risk, driving safety).
- Anticholinergic effects (constipation, urinary retention, blurred vision).
- Confusion or delirium risk in older adults and polypharmacy (Beers).
- Avoid duplicate sedatives and document a stop plan if nightly use develops.
| No | 2025-12-30 |
|---|