Creatine and Anaesthesia: Does It Work?

Creatine and Anaesthesia: Understanding the Interaction

While there are no known direct pharmacological interactions between creatine and anaesthetic drugs, creatine supplementation can indirectly affect anaesthesia planning and safety assessments. Understanding these connections helps ensure safe surgical outcomes (RB et al., 2017) .

How Anaesthesia Drug Dosing Works

Anaesthesiologists calculate drug doses based on several factors:

1. Body weight and composition — determines initial dose
2. Kidney function — affects how quickly drugs are cleared from the body
3. Liver function — affects drug metabolism
4. Age and overall health — influences dose adjustments
5. Other medications — potential drug interactions

Kidney function is particularly important because many anaesthetic and analgesic drugs (or their metabolites) are excreted through the kidneys. If kidney function appears compromised, the anaesthesiologist must adjust doses to prevent drug accumulation and toxicity.

The Creatinine Complication

The primary way creatine affects anaesthesia planning is through serum creatinine levels:

Normal Creatinine Levels

• Without creatine: 0.7-1.2 mg/dL (males), 0.5-1.0 mg/dL (females)
• With creatine supplementation: May elevate to 1.3-2.0 mg/dL

What the Anaesthesiologist Sees

When an anaesthesiologist reviews your pre-operative blood work and sees elevated creatinine:

• They may calculate a reduced glomerular filtration rate (eGFR)
• This suggests potential kidney impairment
• They may reduce doses of renally-cleared drugs
• They may order additional kidney function tests
• Surgery could be delayed pending further evaluation

The Reality

Creatine supplementation raises creatinine without affecting actual kidney function (JR & M, 2000) . The elevation is a marker artifact, not a sign of kidney damage. However, the anaesthesiologist needs to know this to make appropriate decisions.

Pre-Anaesthesia Protocol

Two Weeks Before (Ideal)

• Stop creatine supplementation — allows creatinine to normalise
• Complete pre-operative blood work — with normalised creatinine
• Inform your surgical team — disclose all supplement use

If You Forget to Stop

If your pre-operative blood work shows elevated creatinine and you have been taking creatine:

• Immediately inform your doctor that you use creatine
• Request alternative kidney markers — cystatin C is not affected by creatine supplementation and provides accurate GFR estimation
• BUN-to-creatinine ratio — can help differentiate supplementation from true kidney dysfunction

Specific Anaesthesia Considerations

General Anaesthesia

• No direct interaction with inhalation agents (sevoflurane, desflurane) or intravenous agents (propofol, midazolam)
• Concern is limited to creatinine-based kidney function assessment
• Stop creatine 7-14 days before for clean blood work

Regional Anaesthesia (Spinal, Epidural)

• No known interaction between creatine and local anaesthetics
• Less kidney-dependent than general anaesthesia
• Still inform your anaesthesiologist for completeness

Local Anaesthesia

• For minor procedures under local anaesthesia (dental work, skin procedures), creatine cessation is generally not necessary
• Blood work is not typically required for local procedures

Hydration and Fluid Management

Creatine causes intracellular water retention (water stored inside muscle cells). This has implications for surgical fluid management:

• Accurate fluid assessment: Creatine users may have slightly higher total body water. Anaesthesiologists manage intravenous fluids precisely during surgery.
• Post-operative hydration: After stopping creatine, some of the intracellular water will be released, slightly increasing urine output. This is normal and not a concern.
• Dehydration risk: Ensure adequate hydration in the days before surgery. In Malaysia’s climate, this means drinking at least 2-3L of water daily.

Recovery and Post-Anaesthesia

Immediate Post-Operative Period

During recovery from anaesthesia:

• Focus on hydration and following your surgical team’s instructions
• Do not resume creatine until cleared by your doctor
• Post-operative blood work may include creatinine — wait until results are reviewed before resuming supplementation

Resuming Creatine After Anaesthesia

General timeline for resuming creatine after procedures:

Always verify with your surgical team before resuming (J & V, 2013) .

Communication Template for Your Doctor

When informing your medical team about creatine use, provide:

1. Supplement name: Creatine monohydrate
2. Daily dose: [Your dose, e.g., 5g/day]
3. Duration of use: [How long you have been taking it]
4. Last dose: [When you stopped, if applicable]
5. Reason for use: Athletic performance / muscle building

This information helps the anaesthesiologist accurately interpret your blood work and plan appropriate care.

The Bottom Line

Creatine has no known direct interaction with anaesthetic drugs. The primary concern is that creatine elevates serum creatinine, which can lead to misinterpretation of kidney function during pre-operative assessments. Stop creatine 7-14 days before scheduled procedures, inform your anaesthesiologist about your supplementation history, and request alternative kidney markers (cystatin C) if your creatinine is elevated on pre-operative blood work. Resume supplementation only after receiving clearance from your surgical team.

Further Reading

• Is Creatine Safe?
• creatine dosage guide
• creatine monohydrate
• creatine for muscle building
• creatine and water retention
• buying creatine in Malaysia