Camphor; menthol is a combination of topical analgesics indicated for the temporary relief of minor aches and pains of muscles and joints, such as arthritis, simple backache, muscle strains, sprains, or bruises as well as pain or itching due to poison ivy, oak, or sumac, insect stings, or minor skin irritation, cuts, or scrapes, or sunburn. Camphor is a cyclic ketone for the hydroaromatic terpene group that has been used for medicinal purposes, including its analgesic properties, for centuries. It was originally obtained by distillation of bark chips from the camphor tree, Cinnamomum Camphora but is now produced synthetically. Local effects including mild analgesia, cooling sensation, irritant/counter-irritant effect, and vasodilation have been attributed to topical menthol application. Camphor ingestion has been associated with serious adverse events. Because alternative therapies exist for all indications for camphor therapy, a previous American Academy of Pediatrics (AAP) statement recommended consideration of other therapies that do not contain camphor.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Topical Administration
-Do not apply to wounds or damaged, broken or irritated skin.
-Do not use 1 hour before or within 30 minutes after a bath or shower.
-Avoid contact with the eyes or mucous membranes.
-Do not expose the area treated with camphor; menthol to heat (e.g., heating pad) or direct sunlight.
-Do not use camphor; menthol when sweating, such as from exercise or heat.
-Do not bandage, wrap, or cover the areas where camphor; menthol has been applied.
-Wash hands with soap and water after application.
Cream/Ointment/Lotion Formulations
Cream
-Shake well before using.
-Apply generously to affected area(s) and massage gently until absorbed into skin.
Lotion
-To open, hold cap tightly and turn pump counterclockwise.
Ointment
-Rub well on the affected area.
Transdermal Patch Formulations
-Remove plastic backing from pouch and discard.
-Apply patch to affected skin area. Patch should be comfortable but not tight.
-For sensitive skin, remove patch under water.
Use of menthol has been associated with transient erythema, skin irritation, and/or paresthesias (e.g., burning, stinging, warm sensation) at the site of application. This sensitivity generally diminishes with continued use. However, more serious hypersensitivity reactions may also occur. Contact dermatitis with disseminated pruritus and erythema multiforme lesions have been attributed to the topical application of menthol in a case report. Resolution of symptoms occurred after hospitalization and a 10-day taper of systemic corticosteroid therapy. Rare cases of serious burns have been reported with another menthol-containing product.
Camphor-associated toxicity commonly presents as nausea and vomiting with mental status changes such as excitement, hallucinations, and delirium. Muscular excitability and tremor may precede seizures, which are often followed by respiratory depression and apnea. Arrhythmia, cyanosis, fainting, urinary retention, anuria, albuminuria, transient mild elevated hepatic enzymes, and spontaneous fetal abortion have also been reported with camphor ingestion.
Camphor; menthol is for external use only. It is not for ophthalmic administration; avoid ocular exposure and contact with mucous membranes. Do not bandage, wrap, or cover the areas where camphor; menthol has been applied. Do not apply camphor; menthol to a skin abrasion, wounds, or damaged, broken, or irritated skin. Do not use camphor; menthol 1 hour before or within 30 minutes after a bath or shower. Advise patients using camphor; menthol to avoid the application of heat, including the use of a heating pad, or direct sunlight (UV) exposure to the area of product application immediately before or after use. Do not use camphor; menthol when sweating, such as during strenuous exercise or with an ambient temperature increase.
Camphor ingestion is associated with potential for overdose or poisoning and serious adverse events, including death. Because alternative therapies exist for all indications for camphor therapy, a previous American Academy of Pediatrics (AAP) statement recommended consideration of other therapies that do not contain camphor.
Because some transdermal systems (i.e., patches) contain aluminum or other metal components, advise patients to remove the camphor; menthol topical patch before undergoing magnetic resonance imaging (MRI). Metal components contained in the backing of some transdermal systems can overheat during an MRI scan and cause skin burns in the area where the patch is adhered.
There is no information regarding the use of camphor; menthol during pregnancy.
There is no information regarding the use of camphor; menthol during breast-feeding.
For the treatment of minor arthralgia or myalgia associated with arthritis, bruises, simple backaches, sprains, and strains:
Topical dosage (camphor 4% to 11% and menthol 10% to 16% cream, ointment, or lotion):
Adults: Apply to the affected area(s) up to 3 to 4 times daily as needed. Discontinue use if condition worsens or does not improve within 7 days.
Children and Adolescents 12 to 17 years: Apply to the affected area(s) up to 3 to 4 times daily as needed. Discontinue use if condition worsens or does not improve within 7 days.
Topical dosage (patch):
Adults: Apply 1 patch to the affected area up to 3 times daily as needed. Discontinue use if condition worsens or does not improve within 7 days.
Children and Adolescents 12 to 17 years: Apply 1 patch to the affected area up to 3 times daily as needed. Discontinue use if condition worsens or does not improve within 7 days.
For the treatment of mild pain and pruritus due to poison ivy, oak, or sumac, insect bites or stings, minor skin irritation, cuts, or scrapes, minor burns, or sunburn:
Topical dosage (camphor 0.3% to 0.5% and menthol 0.3% to 0.5% gel or lotion):
Adults: Apply to the affected area(s) up to 3 to 4 times daily as needed. Discontinue use if condition worsens or does not improve within 7 days.
Children and Adolescents 2 to 17 years: Apply to the affected area(s) up to 3 to 4 times daily as needed. Discontinue use if condition worsens or does not improve within 7 days.
Maximum Dosage Limits:
-Adults
3 patches/day; 4 applications/day of cream, gel, lotion, or ointment.
-Geriatric
3 patches/day; 4 applications/day of cream, gel, lotion, or ointment.
-Adolescents
3 patches/day; 4 applications/day of cream, gel, lotion, or ointment.
-Children
12 years: 3 patches/day; 4 applications/day of cream, gel, lotion, or ointment.
2 to 12 years: 4 applications/day of camphor 0.3% to 0.5% and menthol 0.3% to 0.5% gel or lotion; safety and efficacy of other cream, gel, lotion, ointment, or patch products have not been established.
-Infants
Safety and efficacy have not been established.
-Neonates
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.
Patients with Renal Impairment Dosing
Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
*non-FDA-approved indication
There are no drug interactions associated with Camphor; Menthol products.
Camphor is an irritant rubefacient, acting locally on the skin and mucous membranes to induce hyperemia and feelings of comfort and warmth, with sensations of coolness when its vapors are inhaled. Subjective relief of pain is obtained by an indirect counter irritation analgesic effect, representing a masking of moderate to severe deeper visceral pain by a milder pain arising from skin of the same segmented central nervous system level. Local effects including mild analgesia, cooling sensation, irritant/counter-irritant effect, and vasodilation have been attributed to topical menthol application. The exact mechanism of these actions is not well-defined and primarily based on observation. Analgesia may occur directly through interaction with kappa-opioid receptors or indirectly through nociceptor activation and resultant counter-irritant effect. Further, experts have theorized that menthol-induced activation of cold thermoreceptors in the skin may account for the sensation of cool, while activation of nociceptors evokes irritation or burning, and vasodilation. On a cellular level, menthol appears to alter calcium efflux from nerve-cell membranes of cold receptors. Investigators have termed these neurosensory receptors cold- and menthol-sensitive receptor-1 (CMR1), a subfamily of transient receptor potential channel M8 (TRPM8) receptors. The literature is unclear if menthol stimulation of nociceptors is mediated by alterations in cell wall calcium conduction or by, as yet, undefined mechanisms. However, the results of clinical study may explain the dose-dependent sensory effects of menthol. At low concentrations, menthol has been shown to have relative selectivity for CMR1, cold receptors, as compared to nociceptors, pain receptors, while at higher concentrations this selectivity is overcome and menthol acts at both.
Camphor; menthol is administered topically to the skin.
Affected cytochrome P450 isoenzymes and drug transporters: none
-Route-Specific Pharmacokinetics
Topical Route
Camphor is highly lipophilic. It is rapidly absorbed across mucous membranes and has a large volume of distribution. It is oxidized to camphorol, which is conjugated in the liver with glucuronide. Active metabolites are stored in fat deposits and slowly cleared. Most camphor is excreted in the urine. Limited pharmacokinetic study has been conducted with cutaneous camphor; menthol. However, low concentrations of systemic exposure have been demonstrated after the use of camphor and menthol-containing topical patches. Eight-hour application of various numbers of patches resulted in camphor and menthol systemic exposure in all study patients. Average maximum camphor plasma concentrations of 13.5 +/- 4.8 ng/mL, 26.8 +/- 17.2 ng/mL, and 41 +/- 5.8 ng/mL were measured after the use of 93.6 mg, 187.2 mg, and 374.4 mg of camphor, and average maximum menthol plasma concentrations of 7.6 +/- 2.6 ng/mL, 19 +/- 5.4 ng/mL, and 31.9 +/- 8.8 ng/mL were measured after the use of 74.88 mg, 149.76 mg, and 299.52 mg of menthol. Camphor and menthol were no longer detectable at 8 to 12 hours after patch removal after the use of 93.6 mg of camphor and 74.88 mg of menthol, a normal dose for these products. Based on data from each of the 3 administered doses, a camphor terminal half-life of 4 to 8 hours and a menthol terminal half-life of 3 to 6 hours were estimated. Percutaneous penetration has been shown to increase with increasing menthol concentrations.