Co-Phenylcaine Forte Spray Drug Interactions

Propranolol or cimetidine may reduce the clearance of lidocaine hence patients given these drugs together may show signs of lidocaine toxicity. Dose must be adjusted or reduced when necessary and careful and constant monitoring of cardiovascular and respiratory vital signs should be done.
Lidocaine can have either additive effects or antagonistic effects on antiarrhythmic drugs.
Lidocaine prolongs the action of suxamethonium.
Lidocaine and phenytoin have additive cardiac depressant effects.
Antidepressants may interact with phenylephrine. Combining phenylephrine with a tricyclic antidepressant may increase the risk for high blood pressure. Monoamine Oxidase Inhibitors (MAOIs) may increase the effect of oral phenylephrine, resulting in blood pressure elevations and hypertensive crisis. In view of this risk, phenylephrine should not be used in patients taking MAOls or within 2-3 weeks after discontinuation.
Phenothiazines and butyrophenones may reduce or reverse the presser effect of epinephrine. Careful patient monitoring is advised in situations when concurrent therapy is necessary.
Patients on previously-mentioned medications that may interact with lidocaine and phenylephrine must be closely observed. Dose may be adjusted or reduced when necessary. Careful monitoring of cardiovascular and respiratory vital signs should be done.