Terazosin is an alpha-1 blocker used for high blood pressure and benign prostatic hyperplasia (BPH). If someone takes too much, the biggest problem is a sudden drop in blood pressure that can cause dizziness, fainting, or shock. This page tells you how an overdose usually looks, what to do right away, how hospitals treat it, and simple steps to avoid it.
Watch for these clear warning signs after a suspected overdose: feeling very lightheaded or fainting, very low blood pressure, fast or slow heartbeat, severe weakness, nausea, vomiting, or confusion. Some people may have blurry vision or sweaty, pale skin. If a large dose happened recently, symptoms can start within an hour and may last for many hours because terazosin stays in the body for a while.
If you suspect an overdose, call emergency services right away or your local poison control number. If the person is dizzy or faint, lay them flat with legs raised to help blood flow to the brain. Do not give anything by mouth if they are drowsy, vomiting, or can’t swallow. If the person is awake and alert and you are within an hour of the ingestion, emergency staff may consider activated charcoal—but only trained providers should decide that.
Bring the medicine bottle or a picture of it to the hospital. That helps staff know the exact drug and dose. If there are other meds involved—especially blood pressure drugs, heart medicines, or erectile dysfunction drugs like sildenafil—tell the team right away. Those combinations can make low blood pressure much worse.
In the ambulance or ER, providers focus on airway, breathing, and circulation. They’ll give IV fluids first to try to raise blood pressure. If fluids aren’t enough, doctors use medicines called vasopressors (for example norepinephrine) to tighten blood vessels and support pressure. If the heart rate is very slow and causing problems, a drug like atropine can be used. Continuous heart monitoring and repeated blood pressure checks are routine.
There’s no specific antidote for terazosin. Treatment is supportive and based on symptoms. Activated charcoal might be used if the patient arrived very soon after swallowing. Dialysis is not typically helpful for this drug. Doctors will also watch for complications like low oxygen, kidney problems from poor blood flow, and prolonged low blood pressure.
Want to avoid this situation? Keep medicines locked away, follow doses exactly, avoid mixing terazosin with alcohol or sildenafil, and take your first dose at bedtime or while sitting down—many people feel faint the first time they try it. If you ever miss doses or worry about interactions, call your prescriber or pharmacist for advice.
If you’re facing a possible overdose now, get emergency help. Quick action and clear information to medical staff make a big difference.