Clotrimazole: Uses, Side Effects & Dosage Guide

Clotrimazole is an antifungal drug derived from imidazole. Clotrimazole is an ergosterol synthesis inhibitor. Ergosterol is an essential constituent in the cell membrane synthesis. When the synthesis of ergosterol blocks or slows down, it can increase the permeability of the cell membrane, which ultimately leads to fungal or candida cell death. Clotrimazole inhibits the demethylation of 14 alpha lanosterols which is then converted to ergosterol if not inhibited. In this way, the fungal or candida cell can not maintain the integrity of the cell membrane. The ergosterol synthesis inhibition by Clotrimazole is dose-dependent. Besides the antifungal effects of Clotrimazole, it also inhibits the calcium ATPase of sarcoplasmic reticulum and hence can lead to intracellular depletion of calcium ions. By the depletion of calcium channels, the voltage-dependent calcium channels and calcium ions dependent potassium channels become blocked. It is the other property of Clotrimazole besides its antifungal action.

Clotrimazole is widely used for its antifungal property and used to treat various fungal infections, including:

  • vaginal yeast infections
  • oral thrush
  • diaper rash
  • pityriasis Versicolor
  • Ringworm infection
  • athlete’s foot
  • jock itch

Clotrimazole is available in various forms including tablets, creams and gel form. Topical Clotrimazole is most commonly used for the treatment of vaginal yeast infection or vulvovaginal candidiasis and the yeast infection of the skin. Most of the women insert the clotrimazole tablets into the vagina for the treatment for vaginal yeast infection or vulvovaginal candidiasis. Still, creams and gels can also be used for this purpose with the same effectiveness. For the scalp, fungal infections clotrimazole is not indicated because Clotrimazole is not effective in treating scalp fungal infection. If someone is using Clotrimazole as an over the counter drug, then the drug should be discontinued if the signs and symptoms do not improve after the therapy of 7 days.

Clotrimazole is also available in the form of throat tablet for the treatment of oral thrush or oropharyngeal candidiasis, and it is also used prophylactically in patients with neutropenia to prevent oral thrush. Clotrimazole also comes in preparations with steroids like betamethasone for the treatment of :

  • Tinea Corporis also is known as ringworm
  • Tinea Cruris also is known as jock itch
  • Tinea pedis also is known as athlete’s foot

Although the combination of Clotrimazole and betamethasone is FDA approved, but this preparation is not recommended for the treatment of dermatophyte infections because of its many adverse effects. Because of the immunosuppressive effects of glucocorticoid signs and symptoms may reduce for a while, but after that severe infection occurs, which is called a rebound phenomenon; therefore, this combination of Clotrimazole has limited use.

Therefore Clotrimazole should be avoided in combination with other drugs, especially steroids. By avoiding the combination, the following benefits may be occurring:

  • Improve prognosis
  • Decrease the chance of skin atrophy
  • Cost-effective

Topical and oral Clotrimazole can be safely used in both adults and children.

Topical Clotrimazole is considered safe in pregnancy and is categorized as a type B drug in pregnancy.

Clotrimazole is one of the essential medicines in the list of world health organizations. Clotrimazole is also used as an over the counter drug and can be used without any prescription.

But the oral form of Clotrimazole is only available on prescription because of many drug interactions and other life-threatening adverse effects. Therefore it is safe to use this drug as directed by doctors.


Clotrimazole has a broad range of antimycotic is a synthetic imidazole use of Clotrimazole is indicated in the following conditions:

  • Oral candidiasis
  • Vaginal candidiasis
  • Dermatomycoses
  • Treatment of skin infections
    • Athlete’s foot
    • Jock itch
    • Ringworm
    • Pityriasis Versicolor
    • Intertrigo
    • Erythrasma
  • It also uses in the treatment of some gram-positive bacteria
  • And in very high concentration has some activity against trichomonas species
  • For the topical treatment of inflammatory tinea due to Epidermophyton And trichophyton
  • For the treatment of a fungal infection that causes lightening or darkening of the skin of 
    • Neck
    • Chest
    • Arms 
    • And legs


The use of Clotrimazole as an over the counter drug for longer than seven days is not recommended and strongly contraindicated. Consult with your doctor if the signs and symptoms of fungal infections are not improved.

Use of Clotrimazole is contraindicated in the following conditions:

  • Hypersensitivity to imidazole
  • The first trimester of pregnancy
  • Onychomycosis (Topical)
  • Pregnancy
  • Breast-feeding
  • When using Contraceptive devices
  • During Menstruation 
  • Ocular exposure
  • Ophthalmic administration
  • Drug-Drug Interactions

Side effects 

Following are the most countered side effects of Clotrimazole

  • Rash
  • Hives
  • Fever
  • Chills
  • Nausea
  • Vomiting
  • Diarrhoea
  • Unpleasant mouth sensations
  • Foul-smelling vaginal discharge
  • Stomach pain 
  • Local redness
  • Stinging
  • Blistering
  • Oozing
  • Open sores
  • Peeling
  • Swelling
  • Itching
  • Burning at the site of application
  • Flaking of skin
  • Pimples like bump
  • Tenderness
  • Serious Allergic reaction
    • Rash
    • Itching/swelling ( especially of face, tongue and throat)
    • Dizziness
    • Trouble breathing

Tell your doctor if any of the above symptoms appear after the use of imidazole medications or seek medical attention immediately.


Before prescribing Clotrimazole make sure the patient is not allergic to imidazole or any other antifungal drug. Clotrimazole has various drug interactions inquire about the following medications before giving Clotrimazole:

  • Aspirin Low Strength (aspirin)
  • beclomethasone
  • Benadryl (diphenhydramine)
  • betamethasone
  • Colace (docusate)
  • Cymbalta (duloxetine)
  • Fish Oil (omega-3 polyunsaturated fatty acids)
  • Flonase (fluticasone nasal)
  • fluconazole
  • hydrocortisone
  • furosemide
  • pregabalin
  • metronidazole
  • miconazole
  • polyethylene glycol 
  • esomeprazole
  • albuterol
  • montelukast
  • budesonide / formoterol
  • levothyroxine
  • acetaminophen
  • Vitamin B12 (cyanocobalamin)
  • Vitamin C (ascorbic acid)
  • Vitamin D2 (ergocalciferol)
  • Vitamin D3 (cholecalciferol)
  • cetirizine

High-risk groups

High-risk groups for the use of Clotrimazole are :

  • Pregnant ladies
  • Breastfeeding mothers
  • Patients with chronic or active liver disease