Does the amount of water you take with drugs affect the medication? Dr Dong Xiaohui from the Pharmaceutical Department of Shanghai East Hospital gives the answers.
For general oral dosage with tablets, and Chinese medicine granules, 150ml of water is usually required.
For capsules, no less than 300ml of water is required to ensure that the medication has properly entered the body, and to prevent the capsule from becoming soft and sticking to the wall of the throat.
Orally dissolving tablets should be taken after fully dissolved in water, especially for children, to prevent the tablet from expanding in the throat and blocking the airways, which could lead to suffocation.
However, doctors say there are some oral drugs that should not be taken with much water, such as gastric mucosa protective agent.
This kind of agent contains thousands of fine particles that enter the stomach and form a film to cover the damaged gastric mucosa and protect it from gastric acid erosion.
But if you take this kind of medicine with too much water, the drug will dilute quickly and its particles cannot function to cover the damaged gastric mucosa.
The protective film becomes thin and loses effect. Therefore, it's recommended to take such medicine with only a sip of water.
Cough syrup is a more viscous medicine. It will alleviate throat inflammation by adhering to the pharynx.
Drinking too much water will wash the syrup down quickly so that the effective ingredients will no longer be able to treat the inflamed area. If the throat feels dry, refrain from drinking water until over half an hour after the medicine is taken.
Some sublingual medicines that treat cardiovascular diseases such as nitro-glycerine and nitric acid will quickly be absorbed into the lower vein when taken.
Therefore water should not be taken in 30 minutes as it can affect the efficacy.