Taking Prevacid (lansoprazole) can give quick relief from heartburn and acid reflux. But like any drug, it can cause side effects. Below I’ll walk you through the usual ones, the rare but serious problems, and simple steps to lower risk while still getting the benefits.
Most people who use Prevacid experience mild symptoms that go away on their own. Expect headaches, stomach pain, nausea, diarrhea, constipation, gas, or mild dizziness. These often show up in the first days or weeks and usually don’t last.
If mild side effects bother you, try taking the pill before a meal as directed and drink a full glass of water. If symptoms persist beyond a week or get worse, check with your doctor.
Serious reactions are less common but worth knowing. Severe or persistent diarrhea could signal a C. difficile infection — get medical help if you have watery stools, fever, or lots of cramps. PPIs like Prevacid have been linked to low magnesium levels when used long-term; signs include muscle cramps, weakness, or irregular heartbeat.
Using Prevacid for many months or years may raise the chance of bone fractures, especially in older adults, and can lower vitamin B12 absorption over time. Some people develop kidney problems like acute interstitial nephritis; sudden drop in urine output, swelling, or unexplained fatigue are red flags. Allergic reactions (rash, swelling, trouble breathing) are rare but need emergency care.
Drug interactions can matter. Lansoprazole may affect medicines that need stomach acid or use the same liver enzymes. If you take blood thinners (like warfarin), clopidogrel, certain HIV drugs, or methotrexate, tell your doctor so they can check doses or choose a different PPI.
Want to cut your risk? Use the lowest dose that controls your symptoms and limit how long you stay on it, if possible. For long-term users, doctors often check magnesium and B12 levels and assess bone health. Don’t stop suddenly if you’ve used a PPI for a long time — acid rebound can cause worse heartburn. Ask your prescriber about tapering slowly.
If you’re pregnant, breastfeeding, elderly, or have liver or kidney disease, talk with your healthcare provider before starting Prevacid. Even over-the-counter use deserves a quick check-in when you have other health issues or take multiple meds.
Short FAQ: When should I call a doctor? Call right away for severe diarrhea, muscle spasms, fainting, chest pain, yellowing of skin/eyes, sudden swelling, or breathing trouble. For ongoing mild symptoms, schedule a regular follow-up to review need and dose.
Want a quick next step? Keep a symptom diary (what you eat, when you take Prevacid, and how you feel) and share it with your clinician. That makes it easier to find the lowest, safest treatment that works for you.
