What the FDA labels say about taking them together
Caffeine and mexiletine
Mexiletine's FDA label of May 14, 2026 names caffeine in its drug interactions section; the caffeine labels PlainMeds reads (2) do not name mexiletine. The mexiletine label: “Additionally, in one controlled study in five normal subjects and seven patients, the clearance of caffeine was decreased 50% following the administration of mexiletine.”
Check it at the source: the caffeine FDA label on DailyMed (effective July 29, 2026, Sagent Pharmaceuticals); the mexiletine FDA label on DailyMed (effective May 14, 2026, Macleods Pharmaceuticals Limited).
What does the caffeine label say about mexiletine?
Caffeine's label (effective July 29, 2026) and its 1 other brand-application label do not name mexiletine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (caffeine citrate), Sagent Pharmaceuticals, effective July 29, 2026 (SPL set 5f38c395-0093-4afd-89ec-f96e5dc0934a), via openFDA; the full label on DailyMed
What does the mexiletine label say about caffeine?
Mexiletine label, drug interactionsAdditionally, in one controlled study in five normal subjects and seven patients, the clearance of caffeine was decreased 50% following the administration of mexiletine.
Source: FDA drug label (Mexiletine Hydrochloride), Macleods Pharmaceuticals Limited, effective May 14, 2026 (SPL set a61a07f6-0b48-4dcd-ad42-5d90f6e69ab1), 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
| Caffeine | Mexiletine | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.083 per tablet 200 mg tablet | $0.222 per capsule 150 mg capsule |
| Shortage now | No current entry | No current entry |
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