Lonolox® (Minoxidil)

Lonolox® (active ingredient minoxidil) is one of the most potent orally available vasodilators and is used for severe, treatment-resistant high blood pressure when all other medications fail. It opens ATP-modulated potassium channels in vascular smooth muscle and causes a strong dilation of the arteries.

Many people know minoxidil as a hair growth product (e.g., Regaine®). Its blood pressure-lowering effect was discovered first, and the increased hair growth (hypertrichosis) was originally a side effect that was then used for topical application in hair loss.

Lonolox® is only used in combination with a beta blocker (against reflex tachycardia) and a diuretic (against fluid retention). It is not a medication for the standard treatment of high blood pressure, but a reserve medication for extreme cases.

Minoxidil is a potassium channel opener:

Mechanism of action:

• Opens ATP-dependent potassium channels in vascular smooth muscle
• Potassium flows out of the cells → hyperpolarization of the cell membrane
• Calcium channels close → muscle cells relax
• Strong arterial vasodilation
• Drastic reduction in peripheral vascular resistance

Strength of the effect:

• One of the most potent oral vasodilators
• Can lower blood pressure even in the most severe hypertension
• Acts mainly on arteries (hardly on veins)

Counter-regulatory responses (important!):

• Reflex tachycardia (heart rate rises sharply)
• Sodium retention and water retention (weight gain, edema)
• Activation of the renin-angiotensin-aldosterone system
• Therefore ALWAYS in combination with a beta blocker + diuretic!

Onset of action: After 30-60 minutes. Maximum effect after 2-4 hours. Duration of action: 24-72 hours.

Lonolox® (minoxidil) is suitable for:

• Severe, treatment-resistant high blood pressure (when at least 3-4 other medications are not sufficient)
• Malignant hypertension

Requirements for use:

• Only in combination with a beta blocker AND a diuretic
• Close medical monitoring
• Regular echocardiography recommended

NOT suitable as:

• First-line therapy for high blood pressure
• Monotherapy (NEVER use alone!)
• In pheochromocytoma
• In pericardial effusion
• Pregnancy

Severe treatment-resistant high blood pressure:

• Starting dose: 2.5-5 mg once daily
• Slow increase every 3-7 days
• Usual dose: 10-20 mg daily (1-2 doses)
• Maximum dose: 40 mg daily (rarely up to 100 mg)

Children (under supervision):

• Starting dose: 0.2 mg/kg/day
• Maximum dose: 1 mg/kg/day (max. 50 mg)

Concomitant therapy (mandatory!):

• Beta blocker (e.g., bisoprolol 5-10 mg or propranolol 80-160 mg)
• Loop diuretic (e.g., furosemide 40-80 mg)

Available strengths:

• 2.5 mg, 10 mg tablets (Lonolox®)

How to take:

• Once or twice daily
• With or without meals
• Take with water
• Always together with a beta blocker and a diuretic

IMPORTANT – triple therapy: Lonolox® must NEVER be taken alone! It must ALWAYS be taken together with: 1. A beta blocker (against a racing heart) 2. A diuretic (against water retention)

Monitoring:

• Close monitoring of blood pressure and pulse
• Daily weight checks (fluid retention)
• Regular echocardiography (pericardial effusion)
• Check electrolytes and kidney function
• Watch for signs of heart failure

Lonolox® must not be taken in case of:

• Pheochromocytoma
• Pericardial effusion
• Pulmonary hypertension (secondary to mitral stenosis)
• Hypersensitivity to minoxidil
• As monotherapy (NEVER alone!)

Caution in:

• Coronary artery disease (reflex tachycardia can worsen angina)
• Heart failure (fluid retention)
• Renal insufficiency (increased fluid retention)
• After a heart attack (only after stabilization)
• Older patients (increased sensitivity)

Pregnancy: Lonolox® is not recommended during pregnancy. There are only limited data on use in pregnant women. Animal studies have shown harmful effects on reproduction. Increased hair growth in the newborn (neonatal hypertrichosis) has been reported after use during pregnancy. Lonolox® is also not recommended for women of childbearing age who do not use contraception.

Very common (more than 10%):

• Hypertrichosis (increased hair growth all over the body, 80%!)
• Edema and weight gain (without a diuretic)
• Tachycardia (without a beta blocker)
• ECG changes (T wave, approx. 60%, usually temporary)

Common (1-10%):

• Fluid retention
• Headache
• Palpitations
• Chest pain (angina in coronary artery disease)
• Fatigue
• Pericardial effusion (can progress to tamponade!)

Uncommon (0.1-1%):

• Gastrointestinal complaints
• Skin rash
• Breast tenderness

Rare but serious:

• Pericardial tamponade (life-threatening!)
• Severe heart failure due to fluid retention
• Stevens-Johnson syndrome

Hypertrichosis: Increased hair growth (face, arms, back) occurs in about 80% of patients and begins 3-6 weeks after the start of treatment. It is reversible after the medication is stopped (after 1-6 months). This can be particularly distressing for women.

Important combinations (MANDATORY):

• Beta blocker → MUST be given at the same time (against reflex tachycardia)
• Diuretic → MUST be given at the same time (against fluid retention)

Caution with:

• Other blood pressure-lowering drugs → increased hypotension
• NSAIDs → can increase fluid retention
• Guanethidine → orthostatic hypotension
• Erythropoietin → may reduce the effect

Note: Concomitant administration of a beta blocker and a diuretic is not an option but a requirement. Without this concomitant medication, life-threatening complications can occur (severe tachycardia, heart failure, pericardial effusion).