II. Indications
-
Hypertension not controlled with other agents
- Not a first-line Antihypertensive (other agents are preferred)
- Oral Minoxidil as described on this page
- Alopecia
III. Contraindications: Systemic Minoxidil
- Ischemic Heart Disease (Minoxidil provokes Angina)
- Impaired Cardiac Function
- Impaired pulmonary function or preexisting Pulmonary Hypertension
- Severe renal Impairment (esp. CKD 5, GFR <10 ml/min)
IV. Mechanism
- Potent Direct Acting Vasodilator (similar to Hydralazine)
- Decreases Blood Pressure with compensatory reflex Tachycardia
- Minoxidil metabolized to active form Minoxidil sulphate by sulphotransferase enzymes
- Minoxidil sulphate opens plasma membrane ATP-sensitive Potassium channels (KATP channels)
- Results in rapid, direct arteriole Smooth Muscle relaxation
- Reduces Peripheral Vascular Resistance and lowers both systolic and diastolic pressure
V. Dosing: Hypertension in Adults
- Start 2.5 to 5 mg orally daily
- Titrate gradually no more often than every 3 days to 10 to 40 mg orally daily
- Maximum dose: 100 mg/day divided once to twice daily
-
Renal Dosing
- GFR 10 to 50 ml/min: Dose only every 24 hours
- Avoid use in GFR <10 ml/min
VI. Dosing: Hypertension in Children (Not FDA approved)
- Start 0.2 mg/kg orally daily or divided twice daily
- Titrate gradually no more often than every 3 days to 0.25 to 1 mg/kg/day
- Maximum: 50 mg/day
VII. Adverse Effects: Systemic Minoxidil
- Adverse Effects with systemic Minoxidil do not apply to Topical Minoxidil
- Similar to Hydralazine
- Reflex Tachycardia
- Beta Blockers are often used in combination with Beta Blockers to counter reflex Tachycardia
-
Leg Edema
- Due to reflex Sodium and water retention
- Diuretics are often combined with Hydralazine
- Cardiac Muscle Lesions
- Pulmonary Hypertension
- Hirsutism
- Pericardial Effusion or Cardiac Tamponade (asscoiated with underlying renal disease)
VIII. Safety
- Pregnancy Category C
- Safe in Lactation
IX. Metabolism
- Glucuronide Conjugation
X. Drug Interactions
XI. Resources
- Minoxidil Tablet (DailyMed)
XII. References
- (2020) Med Lett Drugs Ther 62(1598): 73-80
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 68-9
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
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Related Studies
minoxidil (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
MINOXIDIL 10 MG TABLET | Generic | $0.21 each |
MINOXIDIL 2.5 MG TABLET | Generic | $0.11 each |
Ontology: Minoxidil (C0026196)
Definition (NCI) | An orally administered vasodilator with hair growth stimulatory and antihypertensive effects. Minoxidil is converted into its active metabolite minoxidil sulphate by sulphotransferase enzymes. Minoxidil sulphate exerts its antihypertensive effect by opening of plasma membrane adenosine triphosphate (ATP)-sensitive potassium channels (KATP channels), thereby directly and rapidly relaxing arteriolar smooth muscle and subsequent reduction of elevated systolic and diastolic blood pressure by decreasing peripheral vascular resistance. This agent's hair growth stimulatory effect may be mediated through its vasodilatory activity, thereby increasing cutaneous blood flow, or due to its direct stimulatory effect on hair follicle cells and forcing them from their resting phase into their active growth phase. |
Definition (MSH) | A potent direct-acting peripheral vasodilator (VASODILATOR AGENTS) that reduces peripheral resistance and produces a fall in BLOOD PRESSURE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p371) |
Definition (CSP) | potent long acting orally effective vasodilator, acting mainly on arterioles, used as an antihypertensive; also applied topically in the treatment of male pattern baldness of the vertex. |
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D008914 |
SnomedCT | 332754004, 387272001, 49577002 |
LNC | LP19149-1, MTHU007401 |
English | Minoxidil, 2,4-Pyrimidinediamine, 6-(1-piperidinyl)-, 3-oxide, Minoxidil [androgen alopecia], 2,3-Dihydro-3-hydroxy-2-imino-6-(1-piperidinyl)-4-pyrimidinamine, 2,4-Pyrimidinediamine, 6-(1-Piperidinyl)-, 3-Oxide, minoxidil, minoxidil (medication), MINOXIDIL, Minoxidil [Chemical/Ingredient], minoxidil products, Minoxidil [androgen alopecia] (product), Minoxidil (product), Minoxidil (substance), Minoxidil [androgen alopecia] (substance) |
Swedish | Minoxidil |
Czech | minoxidil |
Finnish | Minoksidiili |
Russian | MINOKSIDIL, МИНОКСИДИЛ |
Japanese | ミノキシジル, ロニテン, リアップ |
Polish | Minoksydyl |
Spanish | minoxidil (alopecia androgénica), minoxidil (alopecia androgénica) (producto), minoxidil (producto), minoxidil (sustancia), minoxidilo, minoxidil, Minoxidil |
French | Minoxidil |
German | Minoxidil |
Italian | Minoxidil |
Portuguese | Minoxidil |
Ontology: Loniten (C0699464)
Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
MSH | D008914 |
English | Loniten |