Metoprolol and atenolol are prescription medications used in the treatment of high blood pressure and chest pain from coronary artery disease. They can also be used to regulate abnormally rapid heart rates in certain people. While they are both prescribed for essentially the same treatment plans, there are several differences between these medications, including available forms, proper storage instructions, and proper dosing instructions.

Metoprolol and atenolol both manufactured in a variety of forms. Both medications are available in 0.0009 ounce (25 milligram), 0.002 ounce (50 milligram), and 0.004 ounce (100 milligram) tablets. Metoprolol tablets also come in a time-release formula in the same strengths as those of regular tablets, with the added option of a 0.007 ounce (200 milligram) tablet. Manufactures also produce both metoprolol and atenolol injectable medications.

Both medications are designed to be taken either before a meal or just before going to sleep. A typical metoprolol regimen to treat angina may involve taking between 0.004 and 0.015 ounces (100 and 450 milligrams) of the medication orally divided in two even doses daily. Treating angina with atenolol on the other hand, may involve a single daily oral dose of between 0.002 and 0.004 ounces (50 and 100 milligrams) of the medication.

A daily dose of metoprolol to treat high blood pressure is likely to fall between 0.004 and 0.015 ounces (100 and 450 milligrams), while a daily dose of atenolol for high blood pressure usually falls between 0.002 and 0.004 ounces (50 and 100 milligrams). More injections are involved in treating heart attacks with metoprolol than atenolol. The recommended follow-up treatment involving metoprolol tablets also lasts for several days longer than the follow-up treatment with atenolol tablets.

These medications should be stored specific temperature ranges. Metoprolol should be stored at temperatures ranging between 59 degrees Fahrenheit (15 degrees Celsius) and 86 degrees Fahrenheit (30 degrees Celsius). Atenolol on the other hand, is designed to be stored at temperatures between 68 degrees Fahrenheit (20 degrees Celsius) and 77 degrees Fahrenheit (25 degrees Celsius). Metoprolol tablets should be kept in light-resistant containers and protected from moisture.

Despite the fact that both medications are well-tolerated in general, they may cause side effects. Some of the possible side effects from taking either of these medications include fatigue, constipation, abdominal cramps, and nausea. Metoprolol can lead to experiencing certain other side effects including shortness of breath or wheezing. Taking atenolol while pregnant may affect the growth of the fetus or otherwise cause harm to the fetus. Both metoprolol and atenolol may pass into breast milk, these medications should not be taken while breastfeeding.