When you have an episode of
unstable angina, your doctor may give you medicine to
help reduce the stress on your heart and prevent damage to the heart
muscle.
Advantages and disadvantages of some medicines
for unstable angina Medicine | What it does | Advantages | Disadvantages |
|---|
| Beta-blocker | - Reduces workload of the heart by slowing
heart rate and decreasing blood pressure
| - Easy to administer
- Decreases
risk of a heart attack
| - Can lower blood pressure or heart rate
too much
- Can make
heart failure worse
- Can aggravate
asthma
|
| Calcium channel blocker | - Reduces workload on the heart by lowering
blood pressure, slowing heart rate, and increasing blood flow to the
heart
| - Easy to administer
- Can reduce
the number of angina attacks, especially when combined with beta-blockers and
nitroglycerin
| - Can make heart failure worse if
present
- Short-acting calcium channel blockers are not
recommended.
|
| Morphine | - Relieves pain and anxiety
-
Improves shortness of breath
- Lowers blood pressure
| - Helps decrease workload on the heart,
which can improve blood flow
- Reduces anxiety
- Controls
pain
| - Low blood
pressure
- Nausea
- Slowed respiratory rate
|
Beta-blockers
Beta-blockers were developed to help treat people with chest pain.
They can slow your heart rate and reduce your blood pressure, which decreases
the workload on your heart. This in turn decreases the amount of oxygen that
your heart muscle needs.
Beta-blockers should be considered for anyone having a heart attack.
Initially they can be given through an
intravenous (IV) tube, to make sure the medicine works
immediately and to adjust the dose. Later they are given in pill form.
Beta-blockers can slow the heart rate and decrease blood pressure to
low levels, can make heart failure worse, and can trigger asthma attacks in
some people.
Calcium channel blockers
Calcium channel blockers are a group of medicines that share many of
the beneficial effects of beta-blockers. In general, these medicines are not a
first-line therapy for unstable angina. Calcium channel blockers may be used in
some cases, such as when beta-blockers cannot be taken.
Calcium channel blockers can be harmful to people who have moderate
to severe
heart failure because these drugs may decrease the
heart's ability to pump forcefully (contractility). Some calcium channel
blockers, such as verapamil and diltiazem, can disrupt the normal
electrical system of the heart.
Morphine
Morphine helps relieve the pain and anxiety that typically comes
with an episode of unstable angina. As soon as you are more comfortable, it is
easier to control your heart rate and blood pressure and thereby reduce the
work your heart must do. This in turn decreases the amount of oxygen that your
heart needs, which also helps relieve your chest pain.
Doctors commonly give morphine to people whose chest pain does not go
away after taking several nitroglycerin tablets. Morphine provides pain relief
within a few minutes.
Morphine is highly effective, but it can also cause a decrease in
blood pressure and severe nausea or slow the respiratory rate.