Drugs List

Therapeutic Indications

Uses

Alopecia androgenetica

Contraindications

Children under 18 years
Occlusive dressings
Patients over 65 years
Hypertension
Pregnancy
Scalp abnormality (including psoriasis, severe excoriations and sunburn)

Precautions and Warnings

Breastfeeding
Cardiovascular disorder
Porphyria

Advise patient ability to drive or operate machinery may be impaired
Not all available brands are licensed for all age groups
Not all preparations are licensed for use in women
Contains alcohol
Some formulations contain butylated hydroxy toluene (E321)
Some formulations contain cetostearyl alcohol
Some formulations contain propylene glycol
Advise patient to wash hands after use
Avoid contact with diseased or inflamed skin
Avoid contact with eyes
Avoid contact with mucous membranes
Avoid occlusive dressings
Avoid other topical preparations which may cause increased absorption
If accidental contact with the eyes occurs, rinse thoroughly with water
Not to be used on shaved skin
Product is highly flammable - administer away from naked flame
Advise patient to seek medical advice if signs of hypotension occur
An increase in shedding may be seen in the first 2 to 6 weeks of treatment
Discontinue if shedding persists for longer than 2 weeks
Discontinue if hypotension occurs for any reason
Discontinue if persistent redness or irritation occurs
Discontinue if sudden pain in the chest occurs
Avoid inhalation of the product
May be 2 to 4 months before effect is seen

The foam formulation contains butylated hydroxytoluene and cetyl and stearyl alcohol which may cause skin reactions and/or irritation to the eyes or mucous membranes.

Use with caution in patients with acute porphyria. Topical minoxidil can be absorbed, with absorption quoted by the manufacturer in the range of 1 to 2%. Other sources describe up to 4.5% dose absorption.

Pregnancy and Lactation

Pregnancy

Topical minoxidil is contraindicated in pregnancy.

Animal studies have revealed reproductive toxicity at exposure levels that were very high compared to those intended for human exposure. There are limited case reports following exposure in humans. Reports following oral use for hypertension (usually as part of combination therapy) and topical use for alopecia (sometimes with co-morbidities), reveal several cases of multiple congenital abnormalities and heart defects.

Minoxidil is poorly absorbed after topical application from normal intact skin. Systemic absorption of topical minoxidil ranges from 0.3% to 4.5% of the total applied dose. It is not known if minoxidil crosses the placenta, however foetal exposure should be expected due to low molecular weight (about 209) and moderately long elimination half-life (4.2 hours). In addition, there have been cases of hypertrichosis in infants, following in utero exposure, which suggests that minoxidil crosses the placenta (Briggs, 2015).

Schaefer (2015) suggests inadvertent intake of minoxidil does not justify either interruption of pregnancy or invasive diagnostic procedures.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Use topical minoxidil with caution in breastfeeding.

The manufacturer contraindicates the use of minoxidil during breastfeeding.

Minoxidil is excreted into breast milk. Only one case report has been located (minoxidil given orally). This reported no observable effect on the infant.

Hale (2014) suggests it is unlikely that the amount absorbed via topical application would produce clinically relevant concentrations in breast milk.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Acne
Angioedema
Bleeding skin
Blistering
Changes in hair colour
Changes in hair texture
Chest pain
Depression
Dermatitis
Dizziness
Dry skin
Dyspnoea
Erythema
Exacerbation of hair loss
Eye irritation
Facial oedema
Facial swelling
Headache
Hypersensitivity reactions
Hypertension
Hypertrichosis
Hypotension
Increased facial hair
Increased heart rate
Inflamed and dry skin
Irritation (localised)
Musculoskeletal pain
Nausea
Ocular pruritus
Pain
Palpitations
Peripheral oedema
Pruritus
Rash
Skin exfoliation
Skin ulcer
Throat tightness
Tongue swelling
Vomiting
Weight gain

Presentation

Topical formulations containing minoxidil.

Drugs List

Therapeutic Indications

Uses

Alopecia androgenetica

Dosage

Adults

Contraindications

Children under 18 years
Occlusive dressings
Patients over 65 years
Hypertension
Pregnancy
Scalp abnormality (including psoriasis, severe excoriations and sunburn)

Precautions and Warnings

Breastfeeding
Cardiovascular disorder
Porphyria

Advise patient ability to drive or operate machinery may be impaired
Not all available brands are licensed for all age groups
Not all preparations are licensed for use in women
Contains alcohol
Some formulations contain butylated hydroxy toluene (E321)
Some formulations contain cetostearyl alcohol
Some formulations contain propylene glycol
Advise patient to wash hands after use
Avoid contact with diseased or inflamed skin
Avoid contact with eyes
Avoid contact with mucous membranes
Avoid occlusive dressings
Avoid other topical preparations which may cause increased absorption
If accidental contact with the eyes occurs, rinse thoroughly with water
Not to be used on shaved skin
Product is highly flammable - administer away from naked flame
Advise patient to seek medical advice if signs of hypotension occur
An increase in shedding may be seen in the first 2 to 6 weeks of treatment
Discontinue if shedding persists for longer than 2 weeks
Discontinue if hypotension occurs for any reason
Discontinue if persistent redness or irritation occurs
Discontinue if sudden pain in the chest occurs
Avoid inhalation of the product
May be 2 to 4 months before effect is seen

The foam formulation contains butylated hydroxytoluene and cetyl and stearyl alcohol which may cause skin reactions and/or irritation to the eyes or mucous membranes.

Use with caution in patients with acute porphyria. Topical minoxidil can be absorbed, with absorption quoted by the manufacturer in the range of 1 to 2%. Other sources describe up to 4.5% dose absorption.

Pregnancy and Lactation

Pregnancy

Topical minoxidil is contraindicated in pregnancy.

Animal studies have revealed reproductive toxicity at exposure levels that were very high compared to those intended for human exposure. There are limited case reports following exposure in humans. Reports following oral use for hypertension (usually as part of combination therapy) and topical use for alopecia (sometimes with co-morbidities), reveal several cases of multiple congenital abnormalities and heart defects.

Minoxidil is poorly absorbed after topical application from normal intact skin. Systemic absorption of topical minoxidil ranges from 0.3% to 4.5% of the total applied dose. It is not known if minoxidil crosses the placenta, however foetal exposure should be expected due to low molecular weight (about 209) and moderately long elimination half-life (4.2 hours). In addition, there have been cases of hypertrichosis in infants, following in utero exposure, which suggests that minoxidil crosses the placenta (Briggs, 2015).

Schaefer (2015) suggests inadvertent intake of minoxidil does not justify either interruption of pregnancy or invasive diagnostic procedures.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Use topical minoxidil with caution in breastfeeding.

The manufacturer contraindicates the use of minoxidil during breastfeeding.

Minoxidil is excreted into breast milk. Only one case report has been located (minoxidil given orally). This reported no observable effect on the infant.

Hale (2014) suggests it is unlikely that the amount absorbed via topical application would produce clinically relevant concentrations in breast milk.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Acne
Angioedema
Bleeding skin
Blistering
Changes in hair colour
Changes in hair texture
Chest pain
Depression
Dermatitis
Dizziness
Dry skin
Dyspnoea
Erythema
Exacerbation of hair loss
Eye irritation
Facial oedema
Facial swelling
Headache
Hypersensitivity reactions
Hypertension
Hypertrichosis
Hypotension
Increased facial hair
Increased heart rate
Inflamed and dry skin
Irritation (localised)
Musculoskeletal pain
Nausea
Ocular pruritus
Pain
Palpitations
Peripheral oedema
Pruritus
Rash
Skin exfoliation
Skin ulcer
Throat tightness
Tongue swelling
Vomiting
Weight gain

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: July 2018

Reference Sources

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.

Summary of Product Characteristics: Regaine For Men Extra Strength. McNeil Products Ltd. Revised May 2018.
Summary of Product Characteristics: Regaine For Men Extra Strength Scalp Foam 5% w/w Cutaneous Foam. McNeil Products Ltd. Revised May 2018.
Summary of Product Characteristics: Regaine For Women Once a Day Scalp Foam 5% w/w Cutaneous Foam. McNeil Products Ltd. Revised May 2018.
Summary of Product Characteristics: Regaine For Women Regular Strength. McNeil Products Ltd. Revised May 2018.

NICE Evidence Services Available at: www.nice.org.uk Last accessed: 03 July 2018

US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
Available at: https://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT
Minoxidil. Last revised: 09 January 2018
Last accessed: 03 July 2018

The Norwegian Porphyria Centre (NAPOS).
Available at: https://www.drugs-porphyria.org
Last revised: 16 April 2010
Last accessed: 03 July 2018