There are a number of factors that need to be taken into account when determining a patient's proper senna dosage. The age of a patient is an important factor, especially because this drug has a stronger effect on children than adults. The patient's overall health and the condition the drug is being taken for will also influence the amount of senna that a patient takes. Though there are standard dosing recommendations, different manufacturers of the drug may deviate from these recommendations, affecting the dosage of senna that a patient receives.
The main factor when determining the proper senna dosage to use is the age of the patient. Adults and children over the age of 12 are usually given between 15 and 100 milligrams of this herb daily, though most treatments call for a small dose. Children between 6 and 12 years old can be given 50 milligrams of senna in 24 hours, while those between 2 and 6 can only handle 15 milligrams a day, a maximum dose that needs to be broken into two smaller doses and given every 12 hours. There is no set senna dosage for children younger than 2 because treatment with this drug is not recommended for this age group.
Another factor that can determine proper senna dosage is the condition it is being used to treat. Adult patients taking this medication for constipation will generally take about 15 milligrams of senna once a day. Children will take lower a lower senna dosage for constipation, depending on their weight. An adult who needs to completely clear out the stomach and intestines prior to a colonoscopy is usually prescribed a large dose of about 130 milligrams.
The senna dosage a patient receives can also be affected by the manufacturer of the senna. Though medical professionals have reviewed senna and come up with proper dosing recommendations, different manufacturers of the drug may create pills that deviate from those recommendations. Patients should check with pharmacists or doctors before taking a non-standard dose.
Patients with pre-existing medical conditions may receive a modified senna dosage. Liver and kidney damage can make it difficult for the body to metabolize the drug, meaning that they may need to take less of it or take it less frequently, to avoid the possibility of a toxic build up of senna in the body. Other medical conditions may make it dangerous to take standard doses of this drug.