7 DRUG INTERACTIONS Clindamycin phosphate and tretinoin gel should not be used in combination with erythromycin-containing products because of its clindamycin component. (7.1) 7.1 Erythromycin Clindamycin phosphate and tretinoin gel should not be used in combination with erythromycin-containing products due to possible antagonism to the clindamycin component. 7.2 Neuromuscular Blocking Agents Clindamycin has been shown to have neuromuscular blocking properties that may enhance the action of other neuromuscular blocking agents.
Source: FDA drug label - clindamycin phosphate and tretinoin gel 1.2%/0.025%