Phenobarbital
Average User Rating:
Phenobarbital, 3.25 / 5 (4 votes)

Phenobarbital Side Effects

A brown Phenobarbital bottle surrounded by packages that all contain 32 mg dosages.

Serious side effects

Patients should consult their doctor if any of these symptoms occur.
  • Balance problems like staggering walk/clumsiness, double vision, fainting, and severe dizziness
  • Mood problems such as depression, suicidal thoughts and attempts, or any other mood change
  • Severe tiredness/weakness, pale and blistering skin, and fast, slow or shallow breathing, and apnea
  • Allergic reactions (rashes/itches, swelling, trouble breathing)
  • Ataxia- restless muscle movements (in the eyes, tongue, jaw and neck), with fever and sore throat
  • Easy bruising or bleeding, including sores in your mouth and broken blood vessels under the skin
  • Worsened seizures if medication is suddenly stopped, and anxiety
  • Eventual anemia and liver damages, and risk of brain tumors

Common side effects

  • Drowsiness and headaches with increased excitement (mostly in children)
  • Stomach problems including nausea, vomiting, constipation, and loss of appetite
  • Decreased motor activity, memory/concentration problems, and loss of coordination
  • Withdrawal-type reactions like anxiety, hallucinations, twitching, and trouble sleeping after long-time use
  • Confusion, agitation/irritability, and abnormal drug-seeking behavior
  • Drowsiness the following day after a dose and slow heartbeat and blood pressure while sleeping
  • Reduced rapid-eye movement sleep (dreaming stage) and increased reaction to painful stimuli