Hyperlex (Rilmenidine Dihydrogen Phosphate)

Rilmenidine is used in the management of hypertension, a condition characterized by chronically elevated arterial pressure.

• Essential hypertension: reduces systolic and diastolic blood pressure in patients with primary hypertension.
• Mild to moderate hypertension: provides effective control when monotherapy is required.
• Renal hypertension: helps lower blood pressure associated with renal artery disease.

• Rilmenidine acts as a selective agonist of central imidazoline I1 receptors. Activation of these receptors diminishes sympathetic nervous system activity, leading to reduced peripheral vascular resistance and decreased cardiac output. The resulting decline in sympathetic outflow lowers both systolic and diastolic blood pressure without a significant impact on heart rate, distinguishing it from agents that primarily block adrenergic receptors.

Rilmenidine may be associated with several adverse reactions, which are classified by frequency and severity.

Common Side Effects

• Dry mouth: sensation of reduced salivation.
• Dizziness: light‑headed feeling, especially on standing.
• Fatigue: generalized tiredness.
• Headache: mild to moderate intensity.
• Nausea: occasional upset stomach.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure causing fainting.
• Bradycardia: abnormally slow heart rate.
• Hepatic dysfunction: elevated liver enzymes or hepatitis.
• Allergic reactions: rash, pruritus, or angioedema.
• Nephrotoxicity: impaired kidney function in susceptible individuals.

When prescribing Rilmenidine, clinicians should consider several precautionary measures to ensure safe use.

• Initiate therapy at low dose: start with the minimal effective dose and titrate as needed.
• Monitor blood pressure: check regularly to avoid excessive hypotension.
• Assess renal function: evaluate kidney performance before and during treatment.
• Caution in hepatic impairment: adjust use if liver disease is present.
• Avoid abrupt discontinuation: taper gradually to prevent rebound hypertension.
• Store at ambient temperature: keep below 25 °C in the original container, protected from moisture and light.

Rilmenidine can interact with other medicines, altering its antihypertensive effect or increasing adverse risk.

Major Interactions (Avoid)

• Combined use with other central antihypertensives (e.g., clonidine): may cause profound hypotension.
• Concomitant potassium‑sparing diuretics: increase risk of hyperkalemia.
• Strong CYP2D6 inhibitors: may raise rilmenidine plasma levels.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): can blunt antihypertensive response.
• ACE inhibitors or ARBs: additive blood pressure lowering effect, monitor for hypotension.
• Alcohol: may enhance dizziness and hypotensive effects.