Midodrine hydrochloride

Midodrine hydrochloride

Midodrine hydrochloride is a medication primarily used to treat orthostatic hypotension, a condition characterized by a significant drop in blood pressure upon standing. It is an alpha-1 adrenergic agonist that works by constricting blood vessels and increasing blood pressure.

Mechanism of Action

Midodrine hydrochloride is a prodrug, meaning it is converted into its active form, desglymidodrine, in the body. Desglymidodrine acts on the alpha-1 adrenergic receptors in the blood vessels, causing vasoconstriction. This leads to an increase in vascular resistance and, consequently, an increase in blood pressure.

Indications

Midodrine hydrochloride is indicated for the treatment of symptomatic orthostatic hypotension. It is often prescribed when non-pharmacological measures, such as increased salt intake and compression stockings, are insufficient.

Dosage and Administration

The typical starting dose of midodrine hydrochloride is 10 mg, taken three times a day. The dosage may be adjusted based on the patient's response and tolerance. It is recommended to take the last dose of the day at least four hours before bedtime to reduce the risk of supine hypertension.

Side Effects

Common side effects of midodrine hydrochloride include:

• Piloerection (goosebumps)
• Pruritus (itching)
• Urinary retention
• Supine hypertension (high blood pressure while lying down)

Less common but serious side effects may include:

• Bradycardia (slow heart rate)
• Hypertension (high blood pressure)
• Paresthesia (tingling sensation)

Contraindications

Midodrine hydrochloride is contraindicated in patients with:

• Severe organic heart disease
• Acute renal disease
• Urinary retention
• Pheochromocytoma
• Thyrotoxicosis

Precautions

Patients taking midodrine hydrochloride should be monitored for supine hypertension. It is important to measure blood pressure regularly and adjust the dosage as necessary. Patients should also be advised to avoid activities that may exacerbate hypertension, such as heavy lifting and strenuous exercise.

Related Pages

• Orthostatic hypotension
• Alpha-1 adrenergic receptor
• Vasoconstriction
• Blood pressure