Can You Split Toprol XL Tablets?

Megan asked

My doc prescribed me 25 mg Toprol XL. I am really nervous about how it may affect my heart rate. Is there any harm in splitting it and taking only 12.5 mg for the first few days to feel it out? The tablets are scored.

Answer

Yes, Toprol XL (metoprolol extended-release) tablets can be split, which is quite an uncommon characteristic for extended-release products in general.

For most products that have some sort of extended or delayed-release property, splitting or crushing them destroys this mechanism, causing the entire dose of the drug to be released at once.^[1]

This not only ruins the intended effect of the medication (to release the active ingredient over time), it can greatly increase the risk of side effects.

Take for example Oxycontin, which slowly releases the potent opioid drug oxycodone, over a period of 12 hours.^[2]

Crushing or splitting the tablets will cause the entire dose to be delivered all at once, which could cause serious complications including euphoria, respiratory depression, and in serious cases, death.

Fortunately, Toprol XL has a unique extended-release mechanism which allows the tablets to release metoprolol over time, even if they are split.

In fact, as you have mentioned, the tablets are scored, to facilitate splitting if your doctor recommends you do so.

In regard to Toprol XL lowering heart rate, it certainly has that effect on most people.

The prescribing information states an average reduction of heart rate (beats per minute) of 9 to 27, depending on dose, for adults. For children, the reduction in heart rate averages between 5 and 7 beats per minute, although this can vary by individual.^[3]

If you are concerned with a drop in heart rate while on Toprol, talk to your doctor first before adjusting your dose.

25mg is the recommended starting dose for many indications (such as high blood pressure), but there are certain factors where a lower starting dose may be warranted (e.g. in those with an already low heart rate or liver impairment).

So, yes the tablets can be split, but speak with your doctor first about doing so.

Toprol XL Release-Mechanism

Toprol XL tablets contain numerous 'controlled-release' pellets of the active ingredient metoprolol, evenly distributed inside.

Each 'controlled-release' pellet acts as a separate drug delivery unit, and since they are evenly distributed, splitting the tablets do not have an effect on the extended-release properties overall.^[4]

It is important to note that Toprol XL tablets should not be crushed. Crushing the tablets will destroy the individual pellets, and ruin the extended-release properties of the drug.