Simethicone
- Class: Antiflatulent
- Used for: gas and bloating
- Say it: sye-METH-ih-kohn
- Forms: chewable tablet, capsule, oral liquid
Mnemonic: Simethicone pops the bubbles; nothing is absorbed
It is an antifoaming agent that lowers surface tension, so small gas bubbles coalesce and pass more easily. It is not absorbed at all, which makes it one of the safest preparations in the formulary.
It is an antifoaming agent that lowers surface tension, so small gas bubbles coalesce and pass more easily. It is not absorbed at all, which makes it one of the safest preparations in the formulary.
Side effects
Common: few, as it is not absorbed
Serious:
Typical dose
40–125 mg after meals and at bedtime
Taken after meals and at bedtime, when gas collects. There is no maximum worth stating and no titration.
Check yourself
Why is simethicone considered exceptionally safe?
- It is not absorbed from the gut and acts purely physically on gas bubbles
- It is rapidly inactivated by the liver
- It is given at an extremely low dose
- It is excreted unchanged by the kidney
Show answer
A. It is not absorbed from the gut and acts purely physically on gas bubbles
A drug that never enters the bloodstream cannot cause systemic effects or drug interactions. Simethicone's action is mechanical surface chemistry in the gut lumen — which also sets a ceiling on how much it can achieve.
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