What are the effects of 5mg oral Valium (diazepam)?

Effects of 5mg Oral Diazepam (Valium)

Oral diazepam at 5mg typically causes sedation, drowsiness, muscle weakness, and ataxia as its primary effects, with potential for cognitive impairment and psychomotor slowing. 1

Primary Effects

Diazepam (Valium) is a long-acting benzodiazepine with a half-life exceeding 24 hours 2. At the 5mg oral dose, patients can expect:

• Central nervous system effects:

  • Drowsiness and fatigue (most common)
  • Muscle weakness
  • Ataxia (impaired coordination)
  • Potential cognitive impairment
  • Possible amnesia (especially anterograde)

• Other common effects:

  • Dizziness
  • Blurred vision
  • Slurred speech
  • Reduced psychomotor performance

Onset and Duration

Diazepam has a rapid onset of action compared to other benzodiazepines, with effects typically beginning within 30-60 minutes of oral administration 3. Due to its long half-life, effects may persist for 24 hours or longer, especially in:

• Elderly patients
• Patients with hepatic dysfunction
• Those taking other CNS depressants

Safety Considerations

Potential Adverse Reactions

The FDA label highlights several potential adverse effects 1:

• Psychiatric and paradoxical reactions: In some patients, particularly children and the elderly, diazepam may cause stimulation, restlessness, anxiety, agitation, rage, hallucinations, or other paradoxical reactions
• Gastrointestinal: Constipation, nausea
• Cardiovascular: Hypotension
• Special senses: Diplopia (double vision), dizziness

High-Risk Situations

Particular caution is needed in these scenarios:

• Concomitant use with other CNS depressants: The combination of diazepam with opioids or alcohol significantly increases the risk of severe respiratory depression and death 2
• Driving and operating machinery: Patients should not drive or operate machinery for at least 24 hours after taking diazepam 2
• Alcohol use: Patients should avoid alcohol consumption for 24 hours before and after taking diazepam 2

Special Populations

Elderly Patients

Elderly patients have heightened sensitivity to all benzodiazepine effects 2:

• Increased risk of falls and fractures
• Greater cognitive impairment
• Higher risk of delirium
• Lower doses are recommended (typically starting at 2.5mg or less)

Hepatic Dysfunction

Patients with liver disease may experience prolonged drug effects due to impaired metabolism 2:

• Other benzodiazepines like lorazepam or oxazepam are generally preferred in hepatic dysfunction
• If diazepam must be used, dose reduction is necessary

Risk of Dependence

Diazepam has potential for dependence and addiction 4:

• Rapidly absorbed and enters brain tissue quickly, leading to reinforcement
• Causes withdrawal syndrome when discontinued abruptly after prolonged use
• Withdrawal risk increases significantly when used continuously for 8 months or more (43% vs. 5% for shorter durations) 5
• Withdrawal symptoms can be managed by gradually tapering the dose 5

Clinical Pearls

• The 5mg dose is a standard starting dose for most adults but may be excessive for elderly patients or those with hepatic impairment
• Effects on psychomotor function can impair driving ability and increase accident risk
• Regular reassessment of continued need for diazepam is crucial, with evaluation recommended every 2-4 weeks 2
• For long-term anxiety management, non-pharmacological alternatives should be considered due to the risk of dependence 2

Common Pitfalls

• Underestimating duration: Due to its long half-life, diazepam effects may persist longer than expected
• Overlooking drug interactions: Many medications can potentiate diazepam effects
• Abrupt discontinuation: Can lead to withdrawal symptoms including rebound anxiety, insomnia, and rarely seizures
• Assuming safety with alcohol: Even small amounts of alcohol can dangerously potentiate diazepam effects