Can You Cut Or Split Allegra-D?

In our latest question and answer, the pharmacist discusses why you should not cut or split Allegra-D tablets.

May 26, 2019

Nell asked

Can one cut a 24 hrs Allegra-D pill?

At a glance

  • Allegra-D tablets must be taken whole, and not be cut, split, chewed or otherwise altered. Doing so will destrory the extended-release properties of the drug and greatly increase the risk of side effects from getting too high a dose of pseudoephedrine.


Allegra Box With Text - Cutting Allegra-D

No, Allegra-D (fexofenadine; pseudoephedrine) tablets should not be cut, split or otherwise altered. The tablet must be swallowed whole.[1]

Allegra-D tablets have an extended-release mechanism, which releases the active ingredients slowly over time. It is available as either a 12-hour release tablet or 24-hour release tablet.

If you do cut or split the tablet, the extended-release mechanism will be destroyed, causing the entire dose to be delivered at once time. This greatly increases the risk of side effects.[2]

If you are looking to adjust your dose of Allegra-D, you should consider getting each drug separately, as both fexofenadine and pseudoephedrine (the active ingredients in Allegra-D) are available as single drug products.

Increased Side Effects

As mentioned in the overview section, splitting or cutting Allegra-D tablets will ruin the extended-release mechanism, causing the entire dose to be released at once. This is also-known-as 'dose-dumping'.

The decongestant in Allegra-D is pseudoephedrine. The 12-hour version of the product contains 120mg while the 24-hour contains 240mg.

Having 120mg, or worse yet, 240mg of pseudoephedrine given as a single-dose (which is what would occur if the tablets are split) would be considered an overdose of the drug.

Pseudoephedrine, when given in immediate-release formulations, is only recommended to be given at a maximum dose of 60mg every four to six hours.[3]

Therefore, 120mg and 240mg of the drug, given in an immediate-release form, would constitute a two to four-fold overdose.

Pseudoephedrine is a potent vasoconstrictor, and taking too high a dose can (among other things):[4]

  • Increase blood pressure
  • Increase the risk of cardiovascular complications
  • Cause restlessness and insomnia
  • Cause chest pains
  • Increase intraocular pressure

Not only does splitting or cutting Allegra-D increase the risk of side effects (due to the large single dose of pseudoephedrine), it will no longer work for an extended period of time, negating the purpose of the product (which is to work for at least 12 to 24 hours).

  1. ^ Elsevier ClinicalKey: Allegra-D Monograph. ClinicalKey
  2. ^ The Role of Oral Controlled Release Matrix Tablets in Drug Delivery Systems. PubMed
  3. ^ Efficacy and safety of single and multiple doses of pseudoephedrine in the treatment of nasal congestion associated with common cold. PubMed
  4. ^ Pseudoephedrine. PubChem

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