Hytrin

Hy·trin (htrn)

A trademark for the drug terazosin hydrochloride.

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terazosin hydrochloride

Hytrin

Pharmacologic class: Anti-adrenergic (peripherally acting)

Therapeutic class: Antihypertensive

Pregnancy risk category C

Action

Blocks postsynaptic alpha₁-adrenergic receptors, causing vasodilation and decreasing smooth muscle contractions in bladder neck and prostate

Availability

Tablets: 1 mg, 2 mg, 5 mg, 10 mg

⊘Indications and dosages

➣ Hypertension

Adults: Initially, 1 mg P.O., increased slowly as needed up to 5 mg/day. Usual range is 1 to 5 mg/day, not to exceed 20 mg/day.

➣ Benign prostatic hyperplasia

Adults: 1 mg P.O. at bedtime. To achieve desired response, may increase gradually to 2 mg/day, then to 5 mg/day, and then to a maximum of 10 mg/day.

Contraindications

• Hypersensitivity to drug or other quinazoline derivatives

Precautions

Use cautiously in:
• prostate cancer, hepatic disease, dehydration, volume or sodium depletion
• pregnant or breastfeeding patients
• children (safety not established).

Administration

☞ Don't stop therapy suddenly. Dosage must be tapered.
• Know that drug may be given as a single dose at bedtime or in two divided doses.

Route	Onset	Peak	Duration
P.O.	15 min	2-3 hr	24 hr

Adverse reactions

CNS: dizziness, headache, weakness, drowsiness, nervousness, paresthesia, vertigo, fatigue, syncope

CV: orthostatic hypotension (with first dose), rebound hypertension, chest pain, palpitations, peripheral edema, tachycardia, arrhythmias

EENT: blurred vision, conjunctivitis, amblyopia, nasal congestion, sinusitis

GI: nausea, vomiting, diarrhea, abdominal pain, dry mouth

GU: urinary frequency or incontinence, erectile dysfunction, priapism

Musculoskeletal: joint, back, and extremity pain; arthritis

Respiratory: dyspnea

Skin: pruritus

Other: fever, weight gain, flulike symptoms

Interactions

Drug-drug. Estrogens, nonsteroidal anti-inflammatory drugs (NSAIDs), sympathomimetics: decreased antihypertensive effects

Midodrine: antagonism of terazosin's action

Nitrates, other antihypertensives: additive hypotension

Drug-herbs. Ephedra (ma huang): antagonism of terazosin's action

Drug-behaviors. Alcohol use: additive hypotension

Patient monitoring

• Monitor blood pressure. Stay alert for orthostatic hypotension (first-dose effect) when therapy begins.
• Assess cardiovascular status. Report chest pain, peripheral edema, palpitations, and other significant effects.

Patient teaching

• Instruct patient to take at same time every day, with or without food.
☞ Caution patient not to stop therapy abruptly. Dosage must be tapered.
☞ Advise patient to immediately report swelling, breathing difficulty, palpitations, chest pain, and other cardiovascular reactions.
• Tell patient drug may cause erectile dysfunction and other sexual problems.
• Caution patient not to use NSAIDs or drink alcohol.
• Instruct patient to move slowly when sitting up or standing, to avoid dizziness from sudden blood pressure decrease.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, herbs, and behaviors mentioned above.

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Hytrin®

Terazosin, see there