antacids
5 interactions related to antacids
levothyroxine + magnesium
Taking magnesium too close to levothyroxine can modestly reduce how much of the thyroid medicine is absorbed, because magnesium can bind levothyroxine in the gut.
levothyroxine + calcium
Calcium can reduce levothyroxine absorption when the two are taken close together
metformin + vitamin b12
Long-term metformin use can reduce vitamin B12 absorption, sometimes enough to cause deficiency.
phenytoin + calcium
Calcium-containing supplements and antacids can bind phenytoin in the gut and lower how much of the drug is absorbed when the two are taken together, which can reduce phenytoin's blood level. Separately, long-term phenytoin use can reduce calcium absorption by speeding up the breakdown of vitamin D, which is relevant to bone health over time.
gabapentin + antacids
Aluminum- and magnesium-containing antacids reduce the amount of gabapentin absorbed when the two are taken at the same time. The effect is mechanical (the antacid interferes with gabapentin's intestinal uptake) rather than acid- or pH-related, so it can be largely avoided by spacing the two doses a couple of hours apart and taking gabapentin after the antacid.