Losartan is a medication prescribed to manage high blood pressure, also known as hypertension. It also reduces the risk of stroke for individuals with high blood pressure and left ventricular hypertrophy, and treats kidney issues related to type 2 diabetes. While taking any medication consistently is important, missing a dose can occasionally happen, leading to questions about its immediate effects.
Immediate Effects of a Missed Dose
Losartan functions as an angiotensin II receptor blocker (ARB), preventing angiotensin II from tightening blood vessels, allowing them to relax and lower blood pressure. The drug’s therapeutic effect is prolonged by its active metabolite, EXP3174, which is more potent and remains active for 6 to 9 hours, extending its blood pressure-lowering action.
When a dose of losartan is missed, its blood pressure-lowering effect gradually lessens. This can lead to a temporary and modest rise in blood pressure, as the body’s natural blood pressure regulation becomes less inhibited. Studies have shown that after a two-day simulated missed dose period, systolic blood pressure can increase by about 3±2 mm Hg and diastolic by 2±1 mm Hg. For most individuals, a single missed dose is unlikely to cause severe or dangerous symptoms. However, some may notice mild effects such as dizziness, lightheadedness, or a mild headache as blood pressure levels fluctuate.
What to Do If You Miss a Dose
If you miss a dose of losartan, take it as soon as you remember. This applies if it’s still relatively close to your usual dosing time. Following this guideline helps maintain consistent medication levels in your body.
If it’s close to your next scheduled dose, skip the forgotten dose. Take your next dose at its regular time. Avoid taking a double dose to compensate for the missed one. Doubling up on losartan can lead to an excessive drop in blood pressure, known as hypotension, which may cause symptoms like severe dizziness or fainting.
When to Contact a Doctor
While a single missed dose of losartan typically causes no serious complications, contact your doctor if you experience severe symptoms such as a severe headache, chest pain, or fainting. Significant vision changes or sudden confusion also warrant immediate medical attention, as these could indicate a sharp increase in blood pressure.
Also contact your doctor if you frequently miss doses. Your doctor can work with you to explore strategies for better medication adherence or to determine if adjustments to your treatment plan might be beneficial. If you develop severe or prolonged nausea, vomiting, or diarrhea, consult your doctor. These conditions can cause dehydration, potentially leading to a significant drop in blood pressure, and your doctor may advise temporarily pausing your medication.