What the FDA labels say about taking them together
Aminophylline and rifampin
Aminophylline's FDA label of May 22, 2026 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name aminophylline. The aminophylline label: “Drug: Rifampin; Type Of Interaction: Increases theophylline clearance by increasing cytochrome P450 1A2 and 3A3 activity.; Effect**: 20 - 40% decrease”
Check it at the source: the aminophylline FDA label on DailyMed (effective May 22, 2026, Hospira, Inc.); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the aminophylline label say about rifampin?
Aminophylline label, drug interactionsDrug: Rifampin; Type Of Interaction: Increases theophylline clearance by increasing cytochrome P450 1A2 and 3A3 activity.; Effect**: 20 - 40% decrease
Aminophylline label, warningsAge Neonates (term and premature) Children <1 year Elderly (>60 years) Concurrent Diseases Acute pulmonary edema Congestive heart failure Cor pulmonale Fever; ≥102° for 24 hours or more; or lesser temperature elevations for longer periods Hypothyroidism Liver disease; cirrhosis, acute hepatitis Reduced renal function in infants <3 months of age Sepsis with multi-organ failure Shock Cessation of Smoking Drug Interactions Adding a drug that inhibits theophylline metabolism (e.g., cimetidine, erythromycin, tacrine) or stopping a concurrently administered drug that enhances theophylline metabolism (e.g., carbamazepine, rifampin) (see PRECAUTIONS , Drug Interactions, Table II ).
Source: FDA drug label (Aminophylline), Hospira, Inc., effective May 22, 2026 (SPL set 9a663ef3-881f-48bd-2689-3713b24545c2), via openFDA; the full label on DailyMed
What does the rifampin label say about aminophylline?
Rifampin's label (effective February 11, 2026) does not name aminophylline in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Aminophylline | Rifampin | |
|---|---|---|
| Labeled for | Asthma | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.679 per capsule 300 mg capsule |
| Shortage now | No current entry | In shortage |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once