Proamatine: Dosing, Side Effects, Interactions & Contraindication

About Proamatine

ProAmatine ® (midodrine hydrochloride) is a prescription drug given to patients struggling with symptomatic orthostatic hypotension (OH). People with OH tend to feel dizzy when shifting from a passive to a standing position.

Proamatine belongs to the alpha-1 selective adrenergic agonist drug class. There are currently no known clinical benefits or safety data to indicate whether this drug is safe for children or pregnant mothers. We, therefore, recommend speaking to your doctor before taking this medication.

Mechanism of Action

Proamatine elevates blood pressure by invigorating the alpha-1 selective adrenergic agonist receptors, thereby moderating orthostatic hypertension.

Indications

Proamatine is indicated for usage sorely by OH patients that are highly impaired despite other treatments due to the risk of supine blood pressure (BP>200 mmHg systolic). Proamatine’s indication is based on the drug’s effect on elevation in one-minute standing systolic blood pressure.

Contraindications

Proamatine is contraindicated in individuals with urinary retention, severe organic heart disease, thyrotoxicosis, and acute renal disease.

Dosage

Typically, doctors will prescribe a dosage of 10mg three times per day. You must take Proamatine during the day since this is often the time you’ll be in an upright position. Your doctor will likely recommend a 4-hour dosing interval, i.e., at dawn, early morning, midday, and finally another dose in the late afternoon.

Patients with exceptional cases may receive a prescription of 20mg. However, about 45% of such patients experience extreme systolic supine blood pressure. Therefore, your doctor will continue administering Proamatine only if it provides a significant reduction in OH symptoms.

Additionally, experts recommend 2.5-mg doses for patients with abnormal renal functions because Proamatine undergoes renal excretion.

Administration

Proamatine is supplied orally in tablet form in either 2.5-mg, 5-mg, or 10-mg prescription doses.

• 2.5-mg is round, white, has a beveled edge, and an RPC/2.5 marking on one side and 003 on the other
• 5-mg is biplanar, round, orange with an RPC/5 score on one side and 004
• 10-mg is also round, has a beveled edge, and blue with an RPC/10 marking on one side and 007 on the second side

Potential Side Effects

The common side effects of Proamatine include:

• Seizures
• Decreased pulse
• Blurred vision
• Anxiety
• Chest pains
• Severe headaches

Adverse Reactions

The most common adverse reactions noted after various clinical trials include:

• Scalp pruritus
• Supine hypertension
• Goosebumps
• Urinary urge and retention

Warnings

Out of all the adverse reactions noticed during clinical trials, Supine hypertension ended up being the most dangerous one. 13.4% of those who received 10mg of Proamatine showed an increase in blood pressure to 200mmHg.

Precautions

General

Your doctor must perform a preliminary assessment before prescribing Proamatine. Routine monitoring of blood pressure is essential when taking Proamatine simultaneously with other medication, leading to vasoconstriction, such as ephedrine and phenylephrine.

Vagal reflex after receiving Proamatine may lead to a slow heart rate. Also, any OH patient who also has diabetes, visual problems, and takes fludrocortisone acetate can lead to glaucoma or increased intraocular pressure.

Information for Patients

You should know that certain over-the-counter drugs such as flu remedies should be taken cautiously due to the potential risk of supine hypertension.

Drug Interactions

Taking Proamatine and cardiac glycosides simultaneously may increase the risk of bradycardia or arrhythmia.

Carcinogenesis, Mutagenesis, Impairment of Fertility

There’s currently no evidence that indicates carcinogenic effects, mutagenicity, or fertility impairment after taking Proamatine.

Pregnancy and Nursing Mothers

Due to the lack of sufficient data, your doctor will only prescribe Proamatine if the clinical benefit justifies the possible risks to the fetus. Also, it is not yet known if Proamatine is excreted through human milk. For this reason, doctors recommend against prescribing Proamatine for nursing mothers.

Overdosage

Signs of an overdose include:

• Piloerection
• Urinary retention and
• Hypertension

FAQs

What happens if I miss a dose?

Never take double doses. If you miss one dose and it’s time for your second one, only take that dose alone.

What should I watch out for when taking Proamatine?

You may feel dizzy. Therefore, it would be best not to drive or operate machinery until you have understood how Proamatine affects you. You might experience mouth dryness. However, drinking water and eating hard candy will significantly reduce these symptoms. Expect some lifestyle changes, such as using support stockings.

What happens if I overdose?

We recommend seeking immediate help by contacting the poison helpline: 1-800-222-1222.

Where should I store Proamatine?

Like other medicine, store Proamatine out of children’s reach. The ideal temperature should fall anywhere between 15 and 30 degrees Celsius.

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