Precautions and Warnings With H2 Blockers
To ensure a safe treatment process, it is important to understand the precautions and warnings with H2 blockers. For example, H2 blockers can interact with certain other medications. Also, the dose of an H2 blocker must be reduced in people with poor kidney function. In general, you should not take an H2 blocker if you are allergic to an H2 blocker or any inactive components used to make H2 blockers.
H2 Blockers: What Should I Tell My Healthcare Provider?You should talk with your healthcare provider prior to taking an H2 blocker if you have:
- Kidney problems, such as kidney failure (renal failure)
- Liver problems, such as liver failure or cirrhosis
- Acute porphyria
- Any allergies, including allergies to foods, dyes, or preservatives.
Also let your healthcare provider know if you:
- Are pregnant or thinking of becoming pregnant
- Are breastfeeding.
You should also make sure to tell your healthcare provider about all of the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Some Precautions and Warnings With H2 BlockersSome precautions and warnings with H2 blockers to be aware of include:
- H2 blockers can interact with certain other medications. Of all the H2 blockers, cimetidine (Tagamet®) is most likely to interact with other medications.
- The H2 blockers are considered pregnancy Category B medications. This means that they are probably safe for use during pregnancy, though the full risks of taking these medicines while pregnant are not known. Be sure to talk with your healthcare provider about the risks and benefits of using an H2 blocker during pregnancy (see H2 Blockers and Pregnancy).
- H2 blockers pass through breast milk. Therefore, if you are breastfeeding or plan to start breastfeeding, be sure to talk with your healthcare provider about using an H2 blocker (see H2 Blockers and Breastfeeding).
- Because the kidneys clear H2 blockers from the body, the dose of an H2 blocker must be reduced in people will poor kidney function, including kidney failure (renal failure).
- The liver also helps to clear some H2 blockers from the body. Talk with your healthcare provider before taking an H2 blocker if you have liver problems, including liver failure or cirrhosis.
- Some of the symptoms of gastroesophageal reflux disease (GERD), heartburn, or ulcers are similar to stomach cancer symptoms. Just because an H2 blocker helps your symptoms does not rule out the possibility of stomach cancer.
- H2 blockers can cause confusion, agitation, anxiety, hallucinations, disorientation, and other similar problems in some people. Usually, this happens in elderly people who are severely ill and have other medical problems. Let your healthcare provider know right away if you are having any of these side effects during treatment with an H2 blocker.
- For people with acute porphyria, Zantac® (ranitidine) may cause porphyria attacks. Acute porphyria is a condition involving a problem with certain liver enzymes. Zantac is not the best choice for people with acute porphyria.
- Zantac Efferdose® tablets contain phenylalanine. This is important for people with phenylketonuria, as they must limit their intake of phenylalanine. This is not a problem with the other H2 blockers or with regular Zantac tablets.