Clotrimazole

Absorption

Because clotrimazole is generally not significantly absorbed, drug interactions are not a major issue with its use .

Toxicity

Symptoms of overdose include erythema, stinging, blistering, peeling, edema, pruritus, urticaria, burning, and general irritation of the skin, and cramps. As with all topical agents, skin sensitization may result .
Oral LD50 (rat): 708 mg/kg; Intraperitoneal LD50 (rat): 445 mg/kg; Subcutaneous LDLO (rat): 10 g/kg; Oral LD50 (mouse): 761 mg/kg; Subcutaneous LDLO (mouse): 10 g/kg; Intraperitoneal LD50 (mouse): 108 mg/kg;
Overdose
This drug poses no risk of acute intoxication, as it is unlikely to occur following a single vaginal or dermal application of an overdose (application over a large area under conditions favorable to absorption) or accidental oral ingestion. There is no specific antidote .
Effects on Fertility
No human studies of the effects of clotrimazole on fertility have been conducted; however, animal studies have not shown any effects on the drug on fertility .
Use in Pregnancy
There are limited data regarding the use of clotrimazole in pregnant women. Animal studies do not show direct or indirect harmful effects on reproduction. Although the topical application of clotrimazole may result in very low serum and tissue levels, the use of clotrimazole topical cream by pregnant women is not recommended unless it is advised by the prescribing physician. Clotrimazole topical cream should not be used in the first trimester of pregnancy unless it is considered by the physician to be essential to patient well-being .
Use in Breastfeeding
Available pharmacodynamic/toxicological studies in animals have shown excretion of clotrimazole/metabolites in breastmilk. Clotrimazole should not be administered during breastfeeding. Although the topical application of clotrimazole has resulted in very low serum and tissue levels, the use of clotrimazole topical cream by lactating women is not recommended unless it recommended by the prescribing physician .

Description

Clotrimazole is an imidazole antifungal that is active against a wide variety of fungal forms and is effective in many types of fungal infections. It tightly binds sterol 14-α demethylase isoform B from A. fumigatus (K_D = 103 nM) and, like other imidazoles, disturbs the fungal cell membrane. In mammalian cells, clotrimazole potently inhibits the calcium-dependent potassium channels K_v1.3 and IK-1 (IC₅₀ = 6.0 and 0.07 μM, respectively).

Chemical properties

White or pale yellow, crystalline powder.

Originator

Canesten,Bayer,UK,1973

The Uses of Clotrimazole

Clotrimazole is an antifungal agent.

The Uses of Clotrimazole

An antifungal compound and CYP inhibitor.
Clotrimazole (Lotrimin, Mycelex, etc.) is a synthetic imidazole agent. It acts by altering cell membrane permeability. It inhibits the growth of most dermatophyte species, yeast and Malassezia furfur.

The Uses of Clotrimazole

Clotrimazole formally also is an imidazole derivative because of the presence of an imidazole ring in its structure. It is believed that, like miconazole, econazole, and other “pure” representatives of the imidazole class, it also inhibits the biosynthesis of ergosterin in the cytoplasmatic membrane of fungi.
In terms of pharmacological action, clotrimazole is very similar to miconazole. It has a broad spectrum of antifungal activity. It is effective with respect to dermatophytes, and it also has an antimicrobial effect against streptococci and staphylococci. It is also effective with respect to trichomonases. It is very widely used, both externally and vaginally for treating superficial infections. Synonyms of this drug are canesten, empecid, lotrimin, micosporin, and others.

Indications

Topical preparations
Clotrimazole topical cream is indicated for the topical treatment of the following dermal infections , :
Tinea pedis, tinea cruris, and tinea corporis due to Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum
Candidiasis due to Candida albicans
Tinea versicolor due to Malassezia furfur
Diaper rash infected by Candida albicans
In some preparations, clotrimazole may be combined with betamethasone dipropionate, a corticosteroid .
Oral preparations
The oral troche preparation is indicated for the local treatment of oropharyngeal candidiasis . It is also indicated as a prophylactic drug to reduce the incidence of oropharyngeal candidiasis in patients immunocompromised by conditions such as chemotherapy, radiotherapy, or steroid therapy utilized in the treatment of leukemia, solid tumors, or renal transplantation . Troche preparations are not indicated for the treatment of any systemic mycoses .

Background

This drug is a broad spectrum antimycotic or antifungal agent. Clotrimazole's antimycotic properties were discovered in the late 1960s . Clotrimazole falls under the imidazole category of azole antifungals, possessing broad-spectrum antimycotic activity . It is available in various preparations, including creams, pessaries, and troche formulations (slowly dissolving tablets). As well as its antifungal activity, clotrimazole has become a drug of interest in treating several other diseases such as sickle cell disease, malaria and some cancers . The minimal side effect profile of this drug and its uncomplicated metabolic profile have led it to gain widespread acceptance for the treatment of mycotic outbreaks such as vaginal yeast infections as well as athlete's foot .

Definition

ChEBI: A member of the class of imidazoles that is 1H-imidazole in which the hydrogen attached to a nitrogen is replaced by a monochlorotrityl group.

Indications

Clotrimazole (Lotrimin, Gyne-Lotrimin, Mycelex) is a broad-spectrum fungistatic imidazole drug used in the topical treatment of oral, skin, and vaginal infections with C. albicans. It is also employed in the treatment of infections with cutaneous dermatophytes.
Topical use results in therapeutic drug concentrations in the epidermis and mucous membranes; less than 10% of the drug is systemically absorbed. Although clotrimazole is generally well tolerated, local abdominal cramping, increased urination, and transient liver enzyme elevations have been reported.

Manufacturing Process

156.5 g (0.5 mol) o-chlorophenyldiphenylmethyl chloride and 34 g (0.5 mol) imidazole are dissolved in 500 ml acetonitrile, with stirring, and 51 g (0.5 mol) triethylamine are added, whereupon separation of triethylamine hydrochloride occurs even at room temperature. In order to complete the reaction, heating at 50°C is carried out for 3 hours. After cooling, one liter of benzene is added and the reaction mixture is stirred, then washed salt-free with water. The benzene solution is dried over anhydrous sodium sulfate, filtered and concentrated by evaporation; giving 167 g crude 1-(ochlorophenylbisphenylmethyl)-imidazole. By recrystallization from acetone, 115 g (= 71% of the theory) of pure 1-(o-chlorophenylbisphenylmethyl)- imidazole of MP 154° to 156°C are obtained.

brand name

Gyne- Lotrimin (Schering-Plough); Gynix (Teva); Lotrimin (Schering-Plough); Mycelex (Bayer).

Therapeutic Function

Antifungal

General Description

Chemical structure: imidazole

Biochem/physiol Actions

Clotrimazole is a specific inhibitor of Ca2+-activated K+ channels. It is an antifungal azole. Clotrimazole is a derivative of imidazole and has similar antimicrobial action and activity to ketoconazole. It inhibits cytochrome P450-dependent 14α-demethylase, which is critical to ergosterol biosynthesis. The accumulated 14α-methylated sterols change the membrane structure of sensitive fungi, altering cell membrane permeability.

Pharmacokinetics

Clotrimazole is a broad-spectrum antifungal agent that inhibits the growth of pathogenic yeasts by changing the permeability of cell membranes. The action of clotrimazole is fungistatic at concentrations of drug up to 20 mcg/mL and may be fungicidal in vitro against Candida albicans and other species of the genus Candida at higher concentrations . Unfortunately, resistance to clotrimazole, which was rare in the past, is now common in various patient populations .
Clotrimazole is generally considered to be a fungistatic, and not a fungicidal drug, although this contrast is not absolute, as clotrimazole shows fungicidal properties at higher concentrations .

Clinical Use

1-(o-Chloro-α,α-diphenylbenzyl)imidazole (Lotrimin, Gyne-Lotrimin, Mycelex) is a broad-spectrum antifungal drug thatis used topically for the treatment of tinea infections and candidiasis.It occurs as a white crystalline solid that is sparinglysoluble in water but soluble in alcohol and most organic solvents.It is a weak base that can be solubilized by dilute mineralacids.
Clotrimazole is available as a solution in polyethyleneglycol 400, a lotion, and a cream in a concentration of 1%.These are all indicated for the treatment of tinea pedis, tineacruris, tinea capitis, tinea versicolor, or cutaneous candidiasis.A 1% vaginal cream and tablets of 100 mg and 500 mgare available for vulvovaginal candidiasis. Clotrimazole isextremely stable, with a shelf life of more than 5 years.

Synthesis

Clotrimazole, 1-(o-chloro-α,α-diphenylbenzyl)imidazole (35.2.21), is synthesized by reacting 2-chlorotriphenylmethylchloride (35.2.20) with imidazole in the presence of triethylamine.

The starting substance 2-chlorotriphenylmethylchloride is made in various ways. In particular, chlorinating 2-chlorotoluene under light makes 2-chlorotrichloromethylbenzene (35.2.22), which is reacted with benzene in the presence of aluminum chloride to give 2-chlorotriphenylmethylchloride (35.2.20).

An alternative way of making 2-chlorotriphenylmethylchloride is a Grignard reaction between 2-chlorobenzolphenone and phenylmagnesium bromide, followed by substitution of the hydroxyl group in the resulting 2-chlorotriphenylmethylcarbinol (35.2.23) with a chlorine using thionyl chloride.

And finally, reacting phosphorous pentachloride with 2-chlorobenzophenone gives 2
- chloro-1,1-dichlorodiphenylmethane (35.2.24), which is used for the alkylation of benzene in the presence of aluminum chloride and gives 2-chlorotriphenylmethylchloride (35.2.20).

Veterinary Drugs and Treatments

Topical clotrimazole has activity against dermatophytes and yeasts; it may be useful for localized lesions associated with Malassezia. It is not very effective in treating dermatophytosis in cats.
Clotrimazole inhibits the biosynthesis of ergosterol, a component of fungal cell membranes leading to increased membrane permeability and probable disruption of membrane enzyme systems.

storage

Store at RT