Potential drug-drug interactions in outpatient department of a tertiary care hospital in Pakistan: a cross-sectional study

Table 3 Most frequently identified interactions, their levels and potential adverse outcomes

Interacting Pair	Severity levels	Documentation levels	Patients: n (%^a)	Potential adverse outcomes
Ibuprofen – Levofloxacin	Moderate	Fair	50 (2)	Seizures
Ciprofloxacin – Diclofenac	Moderate	Excellent	32 (1.3)	Increased ciprofloxacin plasma concentrations
Aspirin^b – Atenolol	Moderate	Good	24 (1)	Decreased antihypertensive effect
Diclofenac – Levofloxacin	Moderate	Fair	19 (0.8)	Seizures
Diclofenac – Metronidazole	Moderate	Fair	17 (0.7)	Increased exposure of diclofenac
Aspirin^c – Clopidogrel	Moderate	Fair	16 (0.7)	Bleeding
Ciprofloxacin – Metronidazole	Major	Fair	14 (0.6)	QT-interval prolongation
Amlodipine – Diclofenac	Moderate	Good	14 (0.6)	Gastrointestinal hemorrhage and/or antagonism of hypotensive effect
Levofloxacin – Prednisolone	Moderate	Excellent	13 (0.5)	Tendon rupture
Atorvastatin – Clopidogrel	Moderate	Excellent	13 (0.5)	Increased platelet reactivity
Aspirin^b – Glimepiride	Moderate	Good	13 (0.5)	Hypoglycemia
Glimepiride – Levofloxacin	Major	Fair	12 (0.5)	Hypoglycemia or hyperglycemia
Aspirin^c – Bisoprolol	Moderate	Good	12 (0.5)	Decreased antihypertensive effect
Levofloxacin – Thioridazine	Contraindicated	Fair	12 (0.5)	QT interval prolongation
Aminophylline – Levofloxacin	Major	Fair	12 (0.5)	Theophylline toxicity (nausea, vomiting, palpitations, seizures)

-^aPercentage was calculated out of 2400, i.e., total number of patient’s prescriptions
-^bAspirin was prescribed as analgesic doses
-^cAspirin was prescribed as antiplatelet doses

ISSN: 1472-6963