facebook
Subscribe50$/product give away!


Submit an Article to Pharmacy HQ     
Please include the author's name, title, and citations.     
Menthol


Overview and Uses

Doses and Warnings

Chemical Information

Pharmacology

Products Containing Menthol



Overview and Uses

Menthol is in the terpene chemical class and is found in the oil within leaves of the peppermint plant, menthol can also be synthesized in a laboratory.

Menthol has a variety of uses including in the treatment of IBS, abdominal pain, dyspepsia, headaches, spasms of the colon, insect bites, muscle pain, nausea, vomiting, and cough.

Menthol is one of the only agents FDA approved as a topical antitussive. It cools and soothes the throat while decreasing pain sensations.

Menthol appears to have antispasmodic effects on the intestines, easing GI disorders. It lacks clinical evidence to support this.

Menthol is used topically as an antipruritic(stopping itching) for skin conditions that involve inflammation, irritation or itching. Products are typically between 0.5-1% strength for this purpose.

Menthol is used externally as an analgesic for musculoskeletal injuries in concentrations between 2-16%. It should be applied no more than 3-4 times per day for this use.

Menthol is used externally up to 6 times per day to relieve itching, pain and burning sensations from anorectal conditions such as hemorrhoids. Products are typically between 0.1-1% strength for this purpose.

Menthol is also added to other topical preparations in order to increase the absorption of medicinal agents through the skin.

Menthol is used as a flavoring agent in the food and beverage industry.


Pharmacology

Menthol acts on the sensory receptors in the skin. At very low concentrations(less than 1%), it has anesthetic effects, decreasing the amount of pain the skin senses. At higher concentrations(over 1.25%), it causes a sensory response of a cooling sensation, which can distract from and minimize the sensations of pain or irritation. It dose not have any effect on actual body temperature. When used topically, it acts on the sensory receptors called TRPM 8, which causes the cold sensation. TRPM8 is a Transient Receptor Potential cation channel with a variety of subtypes. Some of the subtypes cause hot sensations when activated (capsaicin acts on these receptors). When a substance acts on these receptors in the skin, the sensation "occupies" the sensory pathways, lessening the pain sensation.


Doses

Typical Dose For Irritable Bowel Syndrome:

0.2-0.6ml(187-374mg) enteric coated peppermint oil capsules 3 times per day.

10-30ml peppermint oil solution has been studied for antispasmodic effects in clinical trials.


Warnings

Patients with severe GI disease should avoid use of peppermint oil(menthol).

Caution using peppermint products(tea or topical) in infants and young children, there is a risk of bronchospasms and laryngeal spasm.

Peppermint intake can reduce the absorption of iron.

Antacids or other medications that reduce stomach acidity can alter absorption of enteric coated peppermint oil capsules.

Patients who get skin reactions such as rashes, redness, hives, or irritation should not use menthol.

Patients should stop using topical menthol products if they get hives, rashes, burning, stinging sensations, or swelling of the skin.


Chemistry

Chemical Formula: C10H20O

Molecular Mass: 156.269 g/mol

Boiling point:: 421 degrees F

Melting point: 100 degrees F

IUPAC name: (1R,2S,5R)-5-methyl-2-propan-2-ylcyclohexan-1-ol

Density: 0.904 at 59 degrees F

InChi: 1S/C10H20O/c1-7(2)9-5-4-8(3)6-10(9)11/h7-11H,4-6H2,1-3H3/t8-,9+,10-/m1/s1

LnChl Key: NOOLISFMXDJSKH-KXUCPTDWSA-N

Physical Properties: White solid, crystalline structure, peppermint odor and taste.

Salts/forms available: Solid

Solubility in Water: 1mg/ml or less at room temperature.

Chemical Class: Terpene

Menthol is a secondary alcohol and a terpene. It can react with chromic acid (H2CrO4) to yield a ketone (menthone for menthol's reaction). Acetone is typically used as the solvent for this reaction.

Menthol is a precursor for 8-phenylmenthol, a chiral auxiliary which is used in the process of asymmetric induction, a way to synthesize enantiomerically pure substances when a racemic mixture is not desired.


Products Containing Menthol

Bengay Ultra Strength Pain Relieving Patch - 5% Menthol
Apercreme Heat Pain Relieving Gel - 10% Menthol
Mineral Ice - Menthol 2%
Icy Hot No Mess Applicator - 16% Menthol
Icy Hot Pain Relieving Gel - 2.5% Menthol
ActivOn Topical Analgesic Ultra Strength Arthritis - 4.127% Menthol, Histamine Dihydrochloride 0.025%
Bengay Ultra Strength Pain Relieving Cream -10% Menthol, Methyl Salicylate 30%, Camphor 4%
Icy Hot Cream Extra Strength - Menthol 10%, Methyl salicylate 30%.
Mentholatum Deep Heating Extra Strength Pain Relieving Rub Cream - 8% Menthol, Methyl Salicylate 30%
Mentholatum Ointment - 1.3% Menthol, Camphor 9%
Salonpas Pain Relief Patch - 3% Menthol, Methyl Salicylate 10%
Flexall Plus Maximum Strength Pain Relieving Gel - 16% Menthol, Methyl Salicylate 10%, Camphor 3.1%
Tiger Balm Arthritis Rub Cream - 11% Menthol, Camphor 11%
Arthritis Hot Cream - 10% Menthol, 15% methyl salicylate
Tetramex - menthol/camphor/tetracaine topical
Silvera Pain Relief - capsaicin/menthol/lidocaine topical
Menthocin Patch with Lidocaine - lidocaine/capsaicin/menthol/methyl salicylate topical
Salonpas - capsaicin/menthol topical
Medrox - menthol/methyl salicylate/ capsaicin topical
Delsym Cough + Soothing Action - Dextromethorphan/menthol systemic
Cough Drops
Vapo rubs
Menthol lozenges


Sources

1. National Center for Biotechnology Information. PubChem Compound Database; CID=16666, https://pubchem.ncbi.nlm.nih.gov/compound/16666#section=top (accessed May. 19, 2017)

2. Daniel L. Krinsky, Rosemary R. Berardi, Stefanie P. Ferreri, Anne L. Hume, Gail D. Newton, Carol J. Rollins, Karen J. Teitze. Handbook of Nonprescription Drugs. Washington, DC: American Pharmacists Association, 2012.

3. Brown, William Henry, Brent L. Iverson, Eric V. Anslyn, and Christopher S. Foote. Organic Chemistry. Australia: Cengage Learning, 2009. Print.





Your use of this website constitutes your agreement to the terms and conditions linked below:
Terms and Conditions | Resources
2017 © Copyright PharmacyHQ.com. Questions?
Please contact: pharmacyhq.mail@gmail.com