ORAL MINOXIDIL IN ANDROGENETIC ALOPECIA
One of the biggest developments in the last few years in the treatment of androgenetic alopecia on both males and females is the use of oral minoxidil. This therapy presents important advantages, such as its great effectiveness, its comfort in use and an excellent safety profile.
Minoxidil: History and mechanism of action
Minoxidil is an arteriolar vasodilator drug, used orally since the 80s as a treatment for arterial hypertension (at 10 to 40 mg daily doses). Oddly, a collateral effect was observed as a striking thickening of the patient’s hair, effect we call hypertrichosis. This collateral effect was the cause of many studies with the goal of using this drug to improve hair density in patients with androgenetic alopecia. This was the beginning of topic minoxidil research, that has been in use as an effective treatment for male and female alopecia for over 25 years. As the rest of therapies for androgenetic alopecia minoxidil is a drug that will sort effect as long as it is used, so the treatment should be maintained long term.
The mechanism so that minoxidil improves hair density is manifold:
- It produces an improvement of a hair growth stimulant substance called prostaglandin E2.
- It leads to hair follicles prolonging their growth phase (anagen) and shortening their falling phase (telogen).
- Since it is a vasodilator drug, it improves blood flow in hair follicles.
The use of topic minoxidil has been proved to be a very effective treatment, especially if used twice a day. However, its big disadvantage is that it is complicated for patients to follow this treatment long term, since applying this liquid to the scalp is kind of cumbersome and it dirties hair. Because of this, by 2015, doctors from different countries (Dr. Rodney Sinclair from Melbourne being one of the pioneers) we started using minoxidil orally but to quite lower doses than the ones used to treat arterial hypertension, with the objective of achieving an improvement in hair density on the scalp, without affecting the patient’s arterial tension. Many years of experience and research have been necessary for this, and it allows us to adjust and select the optimum oral minoxidil dosage for each patient, according to their characteristics, alopecia pattern, etc.
Oral Minoxidil: a very effective and comfortable therapy
It is a therapy that has proven its great effectiveness, which improves greatly therapeutical adherence. It is vital to know that the positive effect of improvement induced by minoxidil starts being noticeable from 6 months on, and it reaches its maximum at 12 months. The first months you can notice hair falling off more than usual, a normal effect we call “shedding effect”.
Used dosage
The doses orally used for alopecia depend on many factors: the patient’s sex, the alopecia kind and pattern, concomitant treatments, the patient’s individual characteristics, etc. We generally use doses of 0,25 to 2 mg a day on females and 2,5 to 5 mg a day on males. Effectiveness improves the higher the dose is, but this could also increase some of the side effects, that’s why it is vital individualizing the treatment on each patient. The use of sublingual minoxidil is being currently investigated, and it would allow a similar therapeutical effect but with even a lower dose.
Oral Minoxidil side effects
One of the most important aspects when it comes to using oral minoxidil is getting to know its safety profile and its possible side effects, that naturally (as any drug) can have. The good news is that generally side effects, if they ever develop, are slight and easily manageable.
The most usual side effect of oral minoxidil is by far the increase of body hair in unwanted areas (effect we call “hypertrichosis”). It is a side effect dependent on the used dose (more frequent the higher the dose), appearing in less than 10% of patients that receive a daily dose of 0,5mg or less, and can be greater than 50% on patients that receive a daily dose of 5mg. The most frequent spots are usually the sideburns and the temples
Luckily, the hypertrichosis intensity is mild in most cases and rarely requires patients to quit the treatment due to this effect. Most patients respond great to the dose adjustment. In our experience, in case that patients develop hypertrichosis due to oral minoxidil, in over 50% of the cases this effect will be so slight that we won’t even need to modify the treatment dosage. In the cases where hypertrichosis is noticeable, but the treatment is working correctly and, together with the patients we prefer not modifying the dose, this body hair can be removed with different methods (laser, wax, shavers, etc.).
The rest of side effects are fortunately very rare (less than 5% of the patients) and mild. If they appear, these are reversible by lowering the treatment dose or in the worst case, by quitting the medication.
These effects are mainly:
- 1. Legs or eyelids swelling: since oral minoxidil is a drug that expand blood vessels, some patients can present a slight fluid retention that shows up as legs or eyelids swelling. In may occasions this effect disappears even without changing the medication dose, but in case you notice it you must tell the doctor.
- 2. Arterial tension decrease: oral minoxidil, at the used doses to treat alopecia, usually doesn’t lower arterial tension. However, there are some patients that, because of a special sensitivity to the drug, can notice symptoms arising from a slight decrease of arterial tension, mainly dizziness or palpitations in the first takes of the medication. These possible effects can be minimized starting with an even lower dose, and progressively increasing the dose regarding the tolerance, but it is very important an adequate medical control. In our experience, these effects are very rare at the used doses, and in case they appear, we must check that the formulated dose is correct.
- 3. Headache: as it happens with topic minoxidil, a small percentage of patients can notice a slight headache when taking oral minoxidil. This effect is thought to be because of the minoxidil vasodilator action.
Useful advice when taking oral Minoxidil
LONITEN® vs Pharmaceutical compound:
The use of oral minoxidil for alopecia is nowadays a “usage out of its indication.” This means that there aren’t any commercialized drugs with oral minoxidil with the ideal dose for patients with alopecia. Oral minoxidil on commercially available for the treatment of arterial hypertension is called Loniten®. They are 10mg tablets that can be divided in 2 or 4 pieces to obtain 5 and 2,5mg doses, respectively.
However, there currently a general shortage of this drug in our country, so that’s why we turn to pharmaceutical compounds (meaning that the capsules are “manufactured” at the pharmacy with the prescribed dose for each patient). To avoid mistakes in the pharmaceutical compound with oral minoxidil, this must be made in specialized pharmacies with experience in formulating medication.
What time should I take oral Minoxidil?
There isn’t any research that allow us to answer this question clearly, but generally it is more physiologic, and we usually recommend taking oral minoxidil at night, right before bed. It is not necessary taking it with food, and it is a drug that at the used doses does not usually interact with other routine use drugs. It can be taken together with other treatments for alopecia, such as dutasteride or bicalutamide.
Do I need any specific control when I start taking oral Minoxidil?
In healthy patients it is not necessary any special control further than checking that any of the mentioned side effects appear. However, depending on each patient’s characteristics, their associated diseases and/or other medication they might be receiving, we will recommend a blood test or arterial tension measurement
Can a woman who is looking to have a baby o while she is breastfeeding take oral Minoxidil?
Commercialized oral minoxidil for arterial hypertension (daily dose of 10 to 40mg) is C category during pregnancy. For this reason, we prefer to avoid its usage on pregnant women. On women who are looking to get pregnant, its use could be assessed at very low doses, as long as the treatment is suspended once the pregnancy test is positive. After giving birth, oral minoxidil can be taken again, since it is a drug compatible with breastfeeding according to the American Academy of Pediatrics, regarding available evidence. This is because of its use to treat alopecia is at very low doses (lower than 2mg), which makes the risk of producing defects on the infant practically inexistant. However, I prefer to discontinue its use until after breastfeeding.
Shedding effect: the reason why I notices more hair loss the first months of treatment
One of the effects that worries our patients the most is that, due to topic or oral minoxidil, they notice a higher hair loss during the first 3 to 4 months of treatment. This effect, that can happen in 20 to 30% of the cases, is totally normal and transient, and shouldn’t involve any worries for the patients.
It is known as shedding effect, and it is produced because one of minoxidil action mechanisms is making follicles in telogen phase (thinner hair) falling off, so they are replaced with follicles in anagen phase (thicker hair). This shedding effect is not noticeable to others since it doesn’t produce a loss of hair density, but in case it shows it is more perceptible for the patient, that will notice more hair in the shower, when they style their hair, etc. I usually explain my patients they shouldn’t worry, since this effect involves thinning hairs being replaced with thicker ones, that will be growing in the coming months producing the desired improvement in hair density.
What happens if I quit Minoxidil?
As with any other treatment for alopecia, minoxidil is not curative and its positive effect will be kept as long as the patients maintain the treatment in time. For this reason, it is vital that the treatment strategy is comfortable enough so that therapeutical adherence is good. The fact that the treatment should be maintained continuously doesn’t mean it should be on a daily basis, in fact, many patients keep up with a twice or three times a week therapy. In case that minoxidil is discontinued for over 2 months, follicles that grew thicker will slowly recover the diameter they had before using minoxidil, meaning that we would come back to the starting position. Many patients have the erroneous belief that if we use minoxidil and then we stop it we will have a rebound effect that will leave us worse than how we were before using it, which is fortunately untrue.
Combination of oral Minoxidil with other treatments
One of the big advantages of minoxidil is its great versatility as a treatment for both male and female androgenetic alopecia. Depending on each case, we can use oral minoxidil as a monotherapy or associating it with other treatments, being topic minoxidil, injected therapies such as dutasteride or Platelet-Rich Plasma micro injections, or oral therapies such as antiandrogens (dutasteride, bicalutamide, spironolactone). The use of one or the other depends on the characteristics of each patient, always looking for the best effectiveness-safety-comfort ratio.