ACTION AND MECHANISM - [ANTI-ALOPECIC] with vasodilatory action. - The mechanism of action by which minoxidil stimulates hair growth is not exactly known; a possible alteration of androgen metabolism in the scalp, or a vasodilatory effect that may increase microcirculation around the hair follicle, has been suggested. Applied locally, minoxidil stimulates the growth of keratocytes in vitro and in vivo , does not increase the number of hair follicles but partially converts miniaturized and intermediate hairs into terminal hairs, delaying the progression of androgenetic alopecia in certain patients. This stimulation occurs after four or more months of treatment, and the intensity varies from patient to patient. After 6-12 months of uninterrupted treatment, one-third of patients have shown positive responses. However, discontinuing treatment halts hair growth, and the pre-treatment alopecia may return within three to four months. SPECIAL WARNINGS - Prior to application, a complete medical history and physical examination will be required. - Do not use in the presence of wounds or dermatoses of the scalp until they have healed, as this may increase absorption and cause systemic adverse effects. - There is a possibility of minor local absorption through the scalp, so regular monitoring of blood pressure and heart rate is recommended, one month after starting treatment and every six months thereafter. - Due to its content of ethanol and/or propylene glycol as excipients, frequent applications may cause skin irritation and dryness. - It is advisable to consult a dermatologist if there is no hair growth in women at 8 months using the 2% concentration and in men at 12 months using the 2% concentration or at 4 months with the 5% concentration. - Treatment with topical minoxidil is not indicated when there is no family history of hair loss, or if hair loss is sudden (alopecia areata ) and/or patchy (e.g., scarring alopecia), if hair loss is associated with pregnancy, childbirth, or serious illnesses (e.g., thyroid dysfunction, lupus, loss of patches of hair associated with scalp inflammation, or others), or if the reason for the hair loss is unknown. - Some patients have experienced changes in hair color and/or texture with the use of topical minoxidil. - An increase in hair loss may occur due to the action of minoxidil, which initially causes a shift from the telogen resting phase of hair to the anagen growing phase (shedding of old hairs while new ones grow in their place). This temporary increase in hair loss generally occurs between 2 and 6 weeks after starting treatment and decreases within a couple of weeks (the first sign of minoxidils effect). If hair loss persists, patients should discontinue treatment and consult their doctor. SENIORS The safety and efficacy of topical minoxidil have not been established in patients over 65 years of age, so it is unknown whether they respond differently to the drug, and its use is not recommended in this age group. PATIENT ADVICE - If you have any heart problems, even those you have had in the past, consult your doctor before using minoxidil for the first time. Also, inform your doctor and/or pharmacist if you experience systemic effects such as rapid heartbeat or palpitations; rapid, unexplained weight gain; swelling of the hands, elbows, and face; lightheadedness, dizziness, or fainting; blurred vision; chest, hand, or shoulder pain; scalp irritation; or any other reaction you suspect may be due to the use of this medication. In these cases, discontinue treatment. - This product is intended for application to the scalp, so ingestion or inhalation should be avoided. - For correct application, carefully read the instructions in the leaflet. - Apply to a perfectly dry scalp, starting in the center of the area to be treated, and massage with your fingertips to spread the product over the area to be treated. - It is recommended to wash your hands thoroughly with water before and after application. Special care should be taken to wash your hands after application, especially for women, as there is a risk of hair growth in other areas of the body. - Do not use a hairdryer to speed up hair drying because the hot air can evaporate the product and reduce its effectiveness. - The recommended daily dose should be followed regardless of the extent of the alopecia. Using more than the recommended dose or applying it more frequently will not improve the results. - The patient should be warned that a 4-month pretreatment may be necessary before any signs of hair growth are present. - When treatment is discontinued, growth may cease and return to the initial stage of alopecia within 3-4 months. CONTRAINDICATIONS - Hypersensitivity to any of the components of the preparation. EFFECTS ON DRIVING Based on the pharmacodynamic and general safety profile of minoxidil when administered topically, it is unlikely to affect the ability to drive or operate machinery. PREGNANCY Animal safety : Animal studies have not demonstrated harmful effects on pregnancy, embryonic/fetal development, childbirth, or postnatal development. A risk to the fetus has only been demonstrated at very high exposure levels (compared to those intended for human exposure). Human Safety : There are no adequate and well-controlled studies in pregnant women. Due to the lack of available clinical data on the exposure of pregnant women to topical minoxidil, a risk of fetal harm in humans can be considered, although remote. Therefore, the use of minoxidil during pregnancy is not recommended and should only be used if the benefit to the mother outweighs the potential risk to the fetus. Effects on fertility : No specific studies have been conducted in humans. PHARMACOKINETICS - Absorption: slight absorption (bioavailability 1.4-1.7%). After administration of 1 ml, the amount of minoxidil absorbed is approximately 0.28 mg (20 mg/ml) and 0.85 mg (50 mg/ml). At doses above 2.4-5.4 mg/day, some systemic effect could be expected. This dose could be achieved by applying 5% minoxidil to the entire scalp, not limited to the alopecia. The lowest dose of IV minoxidil observed to produce clinically significant hemodynamic effects in patients with mild to moderate hypertension is 6.86 mg. The results of pharmacokinetic studies indicate that the three most important factors related to increased absorption of minoxidil in the skin are the following: - quantitative increase in the applied dose. - increase in the frequency of application. - reduction of the barrier function of the stratum corneum of the epidermis. Serum concentrations of minoxidil after topical application depend on the rate of percutaneous absorption. The influence of concomitant dermatological disorders on minoxidil absorption has not been determined. After cutaneous application of minoxidil, absorption is not influenced by factors such as: sex, exposure to ultraviolet rays, simultaneous application of a moisturizer, occlusion (use of hairpieces), evaporation of the solvent (use of a hairdryer), or the surface of the application area. - Metabolism: The biotransformation of minoxidil absorbed after topical application is not well understood. It is believed that approximately 60% of absorbed minoxidil is metabolized to minoxidil glucuronide, primarily in the liver. - Elimination: Minoxidil and its metabolites are dialyzable; their elimination is primarily through urine. When topical application is discontinued, approximately 95% of absorbed minoxidil is eliminated within 4 days. INDICATIONS - [ANDROGENIC ALOPECIA]. * Treatment of moderate androgenetic alopecia (hair loss) in men. INTERACTIONS - Tretinoin: increases the percutaneous absorption of minoxidil as a result of an increase in the permeability of the stratum corneum. - Betamethasone dipropionate: increases minoxidil concentrations in local tissues and decreases systemic absorption of minoxidil. - Antihypertensives: Although not clinically proven, minoxidil may increase the risk of orthostatic hypotension in patients receiving concomitant treatment with peripheral vasodilators and antihypertensive drugs such as guanethidine and derivatives. In general, minoxidil should not be applied concomitantly to the same area with other topical products such as corticosteroids, retinoids or occlusive ointments, due to the risk of increased absorption. LACTATION Absorbed minoxidil is systemically excreted in breast milk. Therefore, topical minoxidil should only be used during breastfeeding if the benefit to the mother outweighs the potential risk to the infant. CHILDREN The safety and efficacy of minoxidil administered cutaneously in children and adolescents < 18 years of age has not been evaluated, so it is recommended to avoid its use in this age group. RULES FOR CORRECT ADMINISTRATION - Using the syringe or dispensing pipette: Before applying the product, ensure that your hair and scalp are completely dry. Wash your hands thoroughly before and after applying the solution. a) Measure an exact dose of 1 ml of solution with the syringe or dispensing pipette that comes with the bottle. b) Apply to the scalp, spreading the product with your fingertips over the area to be treated, starting from the center. c) Spread the product with your fingertips over the area to be treated, starting from the center. d) Do not apply the product to other parts of the body. ADVERSE REACTIONS Adverse reactions are described according to each frequency interval, considering very frequent (>10%), frequent (1-10%), unfrequent (0.1-1%), rare (0.01-0.1%), very rare (<0.01%) or of unknown frequency (cannot be estimated from the available data). The most frequent adverse reactions are mild dermatological changes in the application area, such as: peeling, erythema, dermatitis, hypertrichosis (in distal areas), stinging, itching and dryness of the skin (mainly due to the ethanol content). However, the following other adverse reactions may also be observed: - Cardiovascular: infrequent [TACHYCARDIA], [PALPITATIONS], [HYPOTENSION], increased or decreased pulse. - Neurological/psychological: uncommon [HEADACHE], [PARESTHESIA]; very rare [DIZZINESS], [DYSGEUSIA]; frequency unknown [DEPRESSION]. - Respiratory: common [DYSPNEA]; uncommon [SINUSITIS], [RHINITIS]. - Dermatological/hypersensitivity: common [PRURITUS], [SKIN IRRITATION], [CONTACT DERMATITIS], [DRY SKIN], [EXFOLIATIVE DERMATITIS]; uncommon [ALOPECIA] (especially at the start of treatment), patchy hair, [HIRSUTISM]; very rare [ACNE]; frequency unknown [ANGIOEDEMA]. - Genitourinary: [ERECTILE DYSFUNCTION]. - Allergic: very rare [HYPERSENSITIVITY REACTIONS], with [RHINITIS], [SKIN RASHES], generalized [ERYTHEMA] or facial edema. - Musculoskeletal: frequency unknown [MUSCULAR PAIN]. - Ophthalmological: uncommon [tearing], altered vision, vision disturbances. - Optic: infrequent [OTITIS], especially [OTITIS EXTERNA]. OVERDOSE There is no evidence that minoxidil is absorbed in sufficient quantities to cause systemic effects when applied topically. Therefore, when used as directed, an overdose is unlikely. However, if this product is applied to an area where the integrity of the epidermal barrier is compromised (due to trauma, inflammation, or skin disease), the potential for a systemic overdose exists. - Symptoms: Accidental or deliberate overdose after topical application will increase the severity of adverse dermatological reactions, especially itching, dryness, skin irritation, and eczema. Systemic absorption will also be greater, with a consequent increase in the likelihood of systemic side effects, especially cardiac side effects, due to the vasodilatory action of minoxidil (5 ml of 2% solution contains 100 mg of minoxidil, which is the maximum oral dose used in adults for the treatment of high blood pressure). Signs and symptoms of overdose, resulting from the rapid and almost complete absorption of the active ingredient from the gastrointestinal tract, include hypotension, tachycardia, fluid retention with the appearance of edema, pleural effusion, or congestive heart failure. - Treatment: Treatment of overdose resulting from accidental ingestion should be symptomatic and supportive. It may require the use of diuretics for edema, beta-blockers or other sympathetic nervous system inhibitors for tachycardia, and intravenous isotonic sodium chloride solution for hypotension. Sympathomimetics, such as adrenaline and noradrenaline, should be avoided due to the cardiac overstimulation they cause.