Generic name: Guanabenz acetate.

Wytensin is an antihypertensive. It works to reduce blood pressure by reducing nerve impulses to the heart and arteries.

Quick Facts About Wytensin


Used to treat high blood pressure. Works 60 minutes after taking a single dose and may slightly slow heartbeat.

Wytensin Dosage

May take with or without food. Take exactly as prescribed, and on a regular basis for it to be effective. May take several weeks to observe effects. Once symptoms disappear, continue to take.

  • Usual adult dose: 4 milligrams taken 2 times per day to start whether prescribed alone or with a thiazide diuretic. Doctor may increase dose in increments of 4 to 8 milligrams per day every 1 to 2 weeks, up to 32 milligrams taken 2 times per day maximum. Seniors — use with caution.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses. Contact your doctor if you miss 2 or more doses in a row.

Wytensin Side Effects

Overdose symptoms:

excessive contraction of the pupils, irritability, low blood pressure, sleepiness, slow heartbeat, sluggishness. If you suspect an overdose, immediately seek medical attention.

More common side effects: dizziness, drowsiness, dry mouth, headache, weakness.

Less common  or rare Wytensin side effects: abdominal discomfort, aches in arms and legs, anxiety, blurred vision, breast development in males, changes in taste, chest pain, constipation, decreased sex drive, depression, diarrhea, fluid retention, frequent urination, impotence, irregular heartbeat, itching, lack of muscle coordination, muscle aches, nausea, pounding heartbeat, rash, shortness of breath, sleep disturbances, stomach pain, stuffy nose, vomiting. Rare side effect: heartbeat irregularities.


Inform your doctor before combining Wytensin with:

antihistamines such as Benadryl or Tavist; medications that depress the central nervous system such as Halcion, Valium, and phenobarbital.

Avoid alcohol during Wytensin therapy.

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. May appear in breast milk; could affect a nursing infant.

Seniors should use with caution.

Not generally prescribed for children.

  • Do not take if sensitive to or allergic to Wytensin.
  • May cause drowsiness and impair your ability to drive a car or operate machinery. Do not take part in any activity that requires alertness.
  • Use with caution if you have: severe heart disease, stroke, or related disorders; severe liver or kidney failure; or if you had a recent heart attack.
  • Doctor will do blood pressure monitoring if you have kidney or liver disease.


HealthSurvey.org provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Wytensin side effects, please contact your healthcare provider