ketoconazole), or protease inhibitors (e.g., ritonavir), may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution is achieved [see Warnings and Precautions (5.9) ] .
Source: FDA drug label - promethazine, phenylephrine, codeine
ketoconazole), or protease inhibitors (e.g., ritonavir), may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution is achieved [see Warnings and Precautions (5.9) ] .
Source: FDA drug label - promethazine, phenylephrine, codeine
( 7.10 ) Ergot alkaloids, atropine sulfate, steroids, angiotensin, aldosterone, norepinephrine transporter inhibitors, and tricyclic antidepressants : Concomitant use may enhance the pressor response and increase the risk of hypertension. 7.11 Interactions that Augment the Pressor Effect of Phenylephrine The concomitant use of Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution with ergot alkaloids (e.g., methylergonovine maleate); atropine sulfate; steroids (e.g., hydrocortisone); angiotensin; aldosterone; norepinephrine transporter inhibitors (e.g., atomoxetine); and tricyclic antidepressants may enhance the pressor response and increase the risk of hypertension.
Source: FDA drug label - promethazine, phenylephrine, codeine
( 7.12 ) 7.1 Inhibitors of CYP3A4 The concomitant use of Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution with CYP3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g.
Source: FDA drug label - promethazine, phenylephrine, codeine
7.10 Antihypertensive Drugs Due to the antagonistic pharmacologic effects of phenylephrine, one of the active ingredients in Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution, the concomitant use of Promethazine and Phenylephrine HCl and Codeine Phosphate Oral Solution with antihypertensive drugs, including alpha-adrenergic antagonists (e.g., phentolamine); mixed alpha- and beta-adrenoreceptor antagonists; calcium channel blockers (e.g., nifedipine); ACE inhibitors; and centrally acting sympatholytic agents (e.g., guanfacine, reserpine) may reduce their antihypertensive effects.
Source: FDA drug label - promethazine, phenylephrine, codeine