Beta Blockers 101
You could ask your doctor to change to another type of beta blocker. one that does not interact with your central nervouse system as much as the Lopressor class of drugs, which includes Metroprolol.
I switched from Lopressor to Atenolol years ago. Here is some further information.
For simplicity sake (though nothing seems to be that way in medicine today), doctors, using their overall clinical experience, try to prescribe a beta blocker that is felt to be the most appropriate one that will effectively control a particular condition or conditions (dosage must be individualized) and do so hopefully with minimal (tolerable) side effects.
Contraindications, pre-existing medical conditions and drug interactions have to be taken into consideration when prescribing this particular drug as well.
Beta blockers can be cardioselective; decrease in systemic side effects and only affects beta-1 receptors located primarily in the cardiac muscle or non- cardioselective; increase in systemic side effects; and affects beta-1 and the beta-2 receptors (which are located primarily in the bronchial musculature and blood vessels).
Toprol-XL® (metoprolol succinate, extended release) is a beta-1 cardioselective drug. Metoprolol tartrate immediate release is availble as Lopressor® and is reported to be the most widely prescribed and competitive beta-blocker in the world.
In the U.S., Toprol-XL® is primarily indicated for high blood pressure (hypertension) and angina, but like other beta blockers, it can be prescribed for other conditions as determined by a qualified doctor.
Since everyone is unique, and therefore the metabolism responds differently to beta blockers, if a particular beta blocker works well for one individual that does not necessarily mean that it will work well for the next.
A problem with this class of drug is that some beta blockers are known to enter or cross the blood-brain-brain (BBB, actually there are two of them and is described as a protective network of blood vessels and cells that filters blood flowing to the brain) easier than others.
The ones that do this seem to cause more central nervous system (CNS) side effects, such as nightmares, hallucinations, and depression than others that exhibt low penetration characteristics (LPC).
If a beta blocker seems to be ineffective, doctors will either increase the dose or switch to another class of drug that is deemed appropriate.
When a beta blocker dosage is increased, one has to watch out for dose delivered side effects (DDSE) which can be an increase in the severity of present (if any) side effects or the onset of entirely new ones which may or may not cause an iatrogenic condition or disease.
Also, while on this class of drug, blood pressure and pulse/HR should be checked regularly and a doctor should be contacted immediately if/when pulse/HR falls below 50 BPM.
You'll obviously need to discuss your current medication and health status with your cardiologist next month.