The maximum recommended dose of Allegra (fexofenadine) for adults and children 12 and older is 180 mg per day. That means one 180 mg tablet once daily, or one 60 mg tablet twice daily. Both options deliver the same total amount and are equally effective for seasonal allergies and chronic hives.
Standard Adult Dosing
You have two dosing options: a single 180 mg tablet once a day, or a 60 mg tablet taken twice a day. There’s no medical reason to exceed 180 mg total in 24 hours. Taking more won’t relieve your symptoms faster or more completely.
Allegra reaches its peak concentration in your bloodstream about 1 to 2 hours after you swallow it. From there, it stays active for a long time. The drug’s half-life ranges from about 8 to 15 hours, which is why a single daily dose works well for most people. If you take the 60 mg twice-daily version, spacing doses about 12 hours apart keeps levels steady throughout the day.
Allegra-D Has a Stricter Limit
If you’re taking Allegra-D rather than regular Allegra, the rules are tighter because it contains a decongestant (pseudoephedrine) in addition to fexofenadine. For the 24-hour version, the limit is one tablet per day, taken on an empty stomach. The 12-hour version allows one tablet every 12 hours, so two per day maximum. Do not exceed these amounts. The decongestant component can raise blood pressure and cause restlessness, and taking extra tablets stacks that risk.
Children’s Doses Are Lower
Children under 12 should not take adult Allegra tablets. Kids aged 2 to 11 typically use a lower-strength formulation, and children under 2 need an even smaller dose. If your child has kidney problems, the starting dose drops further: 30 mg once daily for children 2 to 11, and 15 mg once daily for children 6 months to under 2 years.
What Happens if You Take Too Much
Allegra has a wide safety margin compared to many medications. Overdose reports are rare, and when they do occur, symptoms tend to be mild: dizziness, drowsiness, and dry mouth. That said, “relatively safe in overdose” is not the same as “safe to double up on.” Sticking to the labeled dose ensures the drug works as intended without unnecessary side effects.
If you accidentally take an extra tablet, you’re unlikely to experience anything serious. If you’ve taken significantly more than the recommended amount and feel unwell, contact Poison Control (1-800-222-1222) for guidance.
Why It Might Feel Like It’s Not Working
If one Allegra tablet isn’t cutting it, the problem usually isn’t the dose. It’s more likely something is interfering with absorption. Two common culprits:
- Fruit juice. Orange juice, apple juice, and grapefruit juice all reduce how much fexofenadine your body absorbs. These juices interfere with transport proteins that move the drug into your cells. The label specifically says not to take Allegra with fruit juices. Stick with water.
- Antacids. Antacids containing aluminum or magnesium (like Maalox or Mylanta) can cut fexofenadine absorption by roughly 40%. If you use antacids, take your Allegra at least 2 hours before them.
Fixing either of these issues can make the same dose noticeably more effective.
Kidney Problems Change the Dose
If you have reduced kidney function, fexofenadine clears your body more slowly, so it builds up to higher levels. The recommended starting dose for adults with any degree of kidney impairment (mild, moderate, or severe) is 60 mg once daily, not the standard 180 mg. This applies regardless of what you’re treating. If you have known kidney disease, your dose should reflect that.
Pregnancy and Breastfeeding
Studies on fexofenadine have not found an increased chance of birth defects, preterm delivery, low birth weight, or miscarriage. No fertility effects have been identified in human or animal studies. Fexofenadine does pass into breast milk in small amounts, but the levels are considered too low to cause problems for a nursing baby.