What is the cause of increased lumbar puncture (LP) opening pressure in a patient with a renal transplant who is already on tacrolimus (FK506) and covered with antibiotics?

From the Guidelines

For a patient with renal transplant on tacrolimus who has increased lumbar puncture (LP) opening pressure and is already on antibiotics, I recommend urgent neurological consultation and consideration of idiopathic intracranial hypertension (IIH) or drug-induced intracranial hypertension. Tacrolimus is a known potential cause of increased intracranial pressure, as noted in the study by 1. Management should include acetazolamide starting at 500mg twice daily, gradually increasing to 1000-2000mg daily in divided doses if needed and tolerated. Monitor renal function closely as acetazolamide can affect transplant function, and consider the potential side effects of tacrolimus, such as nephrotoxicity, as mentioned in the study by 1. If symptoms are severe (visual changes, severe headaches), consider therapeutic LP to remove CSF and reduce pressure. For patients not responding to acetazolamide or with severe symptoms, topiramate 25mg daily, increasing gradually to 50mg twice daily, can be considered as an alternative. Weight loss should be encouraged if the patient is overweight. Tacrolimus levels should be checked and dose adjustment considered in consultation with the transplant team, taking into account the recommended trough levels of 4-8 ng/ml thereafter, as suggested by 1. Regular ophthalmology follow-up is essential to monitor for papilledema and visual field changes. The mechanism involves tacrolimus potentially altering CSF production or absorption, while maintaining immunosuppression remains critical to prevent transplant rejection. Key considerations in managing this patient include:

• Close monitoring of renal function and potential adjustment of tacrolimus dose
• Regular ophthalmology follow-up to monitor for papilledema and visual field changes
• Consideration of alternative treatments, such as topiramate, if symptoms are severe or not responding to acetazolamide
• Encouragement of weight loss if the patient is overweight
• Urgent neurological consultation to rule out other causes of increased intracranial pressure.

From the Research

Increase in LP Opening Pressure in Patient with Renal Transplant on Tacrolimus

• The patient is already covered with antibiotics, which rules out infection as a cause of increased LP opening pressure 2, 3.
• Tacrolimus, an immunosuppressant, can cause neurological side effects, including increased intracranial pressure, which may lead to increased LP opening pressure 2, 3, 4.
• The studies suggest that tacrolimus-induced neurotoxicity can be a cause of increased LP opening pressure in patients with renal transplants 2, 3.
• Monitoring of tacrolimus levels and adjusting the dose accordingly may help prevent neurotoxicity and increased LP opening pressure 5, 6.
• Switching to a different immunosuppressant, such as cyclosporine, may be considered if tacrolimus is suspected to be the cause of increased LP opening pressure 2.

Possible Causes of Increased LP Opening Pressure

• Tacrolimus-induced neurotoxicity 2, 3, 4
• Infection (although the patient is already covered with antibiotics) 4
• Other causes of increased intracranial pressure, such as cerebral venous sinus thrombosis or idiopathic intracranial hypertension 3

Management of Increased LP Opening Pressure

• Monitor tacrolimus levels and adjust the dose accordingly 5, 6
• Consider switching to a different immunosuppressant, such as cyclosporine 2
• Investigate other possible causes of increased intracranial pressure and manage accordingly 3