During a D-test, bacteria of the iMLSB phenotype demonstrate in vitro erythromycin-induced in vitro resistance to clindamycin. This is because of the activity of the macrolide-inducible plasmid-encoded erm gene.To perform a D-test, an agar plate is inoculated with the bacteria in question and two drug-impregnated disks (one with erythromycin, one with clindamycin) are placed 15–20 mm apart on the plate. If the area of inhibition around the clindamycin disk is "D" shaped, the test result is positive. Despite the apparent susceptibility to clindamycin in the absence of erythromycin, a positive D-test precludes therapeutic use of clindamycin. This is because the erythromycin-inducible erm gene is prone to mutations causing the inducible activity to switch to constitutive (permanently switched on). This in turn, may lead to the therapeutic failure of clindamycin. If the area of inhibition around the clindamycin disk is circular, the test result is negative and clindamycin can be used. Malaria
Given with chloroquine or quinine, clindamycin is effective and well tolerated in treating Plasmodium falciparum malaria; the latter combination is particularly useful for children, and is the treatment of choice for pregnant women who become infected in areas where resistance to chloroquine is common. Clindamycin should not be used as an antimalarial by itself, although it appears to be very effective as such, because of its slow action. Patient-derived isolates of Plasmodium falciparum from the Peruvian Amazon have been reported to be resistant to clindamycin as evidenced by in vitro drug susceptibility testing.
Clindamycin is more effective than lincomycin.The X-ray crystal structures of clindamycin bound to ribosomes (or ribosomal subunits) derived from Escherichia coli, Deinococcus radiodurans, and Haloarcura marismortui have been determined; the structure of the closely related antibiotic lincomycin bound to the 50S ribosomal subunit of Staphylococcus aureus has also been reported. Society and culture
Economics
Clindamycin is available as a generic medication and is relatively inexpensive. Available forms
Clindamycin preparations that are taken by mouth include capsules (containing clindamycin hydrochloride) and oral suspensions (containing clindamycin palmitate hydrochloride). Oral suspension is not favored for administration of clindamycin to children, due to its extremely foul taste and odor. Clindamycin is formulated in a vaginal cream and as vaginal ovules for treatment of bacterial vaginosis. It is also available for topical administration in gel form, as a lotion, and in a foam delivery system (each containing clindamycin phosphate) and a solution in ethanol (containing clindamycin hydrochloride) and is used primarily as a prescription acne treatment.Several combination acne treatments containing clindamycin are also marketed, such as single-product formulations of clindamycin with benzoyl peroxide—sold as BenzaClin (Sanofi-Aventis), Duac (a gel form made by Stiefel), and Acanya, among other trade names—and, in the United States, a combination of clindamycin and tretinoin, sold as Ziana. In India, vaginal suppositories containing clindamycin in combination with clotrimazole are manufactured by Olive Health Care and sold as Clinsup-V. In Egypt, vaginal cream containing clindamycin produced by Biopharmgroup sold as Vagiclind indicated for vaginosis.Clindamycin is available as a generic drug, for both systemic (oral and intravenous) and topical use.