From the Guidelines
Primidone can cause significant side effects, including behavioral disturbances, irritability, and sleep disturbances, as reported in a study published in Pediatrics in 2008 1. When considering the use of Primidone, it is essential to weigh the potential benefits against the potential risks, particularly in terms of morbidity, mortality, and quality of life. Some of the common side effects associated with Primidone include:
- Behavioral disturbances
- Irritability
- Sleep disturbances These side effects are particularly notable in children, as reported in the study by Minigawa and Miura, where 29 out of 32 children had derived phenobarbital levels below therapeutic levels, suggesting that Primidone itself may be active in preventing seizure recurrence 1. In terms of management, it is crucial to monitor patients closely for any adverse effects and adjust the dosage accordingly. The typical dosage of Primidone is 15 to 20 mg/kg per day, as stated in the study published in Pediatrics 1. It is essential to prioritize the potential risks and benefits of Primidone, particularly in terms of its impact on morbidity, mortality, and quality of life, and to carefully monitor patients for any adverse effects 1.
From the FDA Drug Label
The most common side effects of Primidone include: problems with walking and moving feelings of dizziness, spinning, or swaying (vertigo) Primidone may cause other serious side effects including: Sleepiness that can be severe, especially when you first start taking primidone. Primidone may rarely cause blood problems Symptoms may include: fever, swollen glands, or sore throat that come and go or do not go away frequent infections or an infection that does not go away tiredness shortness of breath Primidone may rarely cause allergic reactions Symptoms may include: skin rash hives sores in your mouth blistering or peeling skin
The possible side effects of Primidone include:
- Sleepiness that can be severe
- Blood problems such as fever, swollen glands, sore throat, frequent infections, tiredness, and shortness of breath
- Allergic reactions such as skin rash, hives, sores in the mouth, and blistering or peeling skin
- Problems with walking and moving
- Dizziness, spinning, or swaying (vertigo) 2 2
From the Research
Side Effects of Primidone (Mysoline)
- Common side effects of primidone include drowsiness, sedation, and behavioral disorders 3, 4
- The rate of onset of side effects was examined in pediatric outpatients, and results showed that primidone had a side effect rate of 29% 3
- Serious side effects requiring withdrawal of treatment occurred at a rate of 8% with primidone 3
- Behavioral disorders involving excitement were most common with primidone at low plasma levels, while behavioral disorders involving depression occurred at high plasma levels 3
- A study comparing primidone and carbamazepine found that there were somewhat more side effects with carbamazepine than with primidone, although none were serious 5
- In a prospective study with computerized quantitative analysis, side effects of primidone (especially drowsiness and sedation) were common at 4 weeks and 3 months but tended to subside thereafter 4
- Three patients discontinued primidone prematurely due to sedative effects outweighing the potential therapeutic benefit 4
- Early side effects are common when primidone is used to treat essential tremor, with as many as one-third of patients failing to tolerate the tablets 6
- A randomized trial comparing primidone initiation schedules found that side effects in the first 48 hours of treatment were equally common in both the suspension and tablet groups 6