Preparation H ointment works for hemorrhoidal symptoms by temporarily shrinking tissue to alleviate symptoms such as burning, itching and discomfort, notes manufacturer Pfizer Consumer Healthcare. The ointment can be applied to the affected area up to four times daily, most notably at night, in the morning and after bowel movements. If symptoms do not improve in seven days, users should see a doctor.
Active ingredients of Preparation H include mineral oil, petrolatum and phenylephrine HCl. The first two ingredients are protectants, and phenylephrine HCl is a vasoconstrictor, according to the label from Pfizer Consumer Healthcare. WebMD explains that other ingredients such as zinc oxide, cocoa butter and starch form a protective barrier between stools and the irritated rectum. The goal of Preparation H and similar products is to make bowel movements less uncomfortable.
Drugs.com reveals Preparation H blocks pain signals in nerve endings in the skin, and the ointment is a topical anesthetic. The risk of it interacting with other medications is low because Preparation H does not enter the bloodstream.
People with certain medical conditions may not be able to take Preparation H, according to Drugs.com. Patients who have heart issues, high blood pressure, thyroid problems, diabetes or prostate problems should consult with a doctor before taking this remedy. WebMD notes that the medicine rarely has side effects when it is taken as directed.