Cholesterol lowering drug Lipitor causes memory and concentration loss, confused for ADHD*

keywords: cardiovascular, cerebrovascular, disease, statins, cholesterol, heart surgery

Occupation:
Consultant

Question:
Mr X presented with subjective memory, attention and concentration complaints, which he thought might be ADHD.

Problem:
Mr X questioned whether there could be something neurological since previously he did not respond to the traditional medicinal treatment for ADHD.

Complications:
Mr X had undergone a triple bypass and was on a number of medications.

Outcome:
We used objective brain function analysis to evaluate the Mr X?s condition. This revealed a pattern of inattentiveness and mild slowing and memory weaknesses.

Neurophysiological findings indicated evidence for a slowing of cortical rhythms and reduced cortical arousal. Minor information processing abnormalities were also present

Further investigation indicated a possible drop in brain cholesterol levels due to statin therapy with Lipitor (atorvastatin).

Statins are important for the prevention of vascular disease. A minority of patients show cognitive impairments (such as memory loss) that occurs with slow onset (up to 1 year post-treatment) and progressively worsening symptoms (King et al., 2003; Orsi et al., 2001). In a number of patients, cognitive impairments have been found to resolve within 1 to 4 weeks of statin discontinuation (King et al., 2003; Orsi et al., 2001; Wagstaff et al., 2003).

Theoretical explanations for statin-related cognitive impairments are thought to be due to a break down of myelin due to a reduction in CNS cholesterol, critical for the formation of myelin and membrane integrity (King et al., 2003; Orsi et al., 2001).

Simvastatin and atorvastatin have very high lipophilicity, meaning they more easily cross the blood-brain barrier (King et al., 2003; Orsi et al., 2001) and are more likely to affect CNS cholesterol physiology. A meta analysis of 36,062 persons receiving a statins and 35,046 receiving a placebo indicated that atorvastatin compared with other statins was associated with the greatest risk of adverse events (Silva et al., 2006).

Conclusion:
Our tests revealed a significant brain disturbance. In conjunction with other clinical data it was concluded that Mr Xs brain function disturbance was due to a cholesterol lowering drug Lipitor. This medication was ceased and the patient returned to his normal level of functioning.

It was recommended that if Mr X requires further prescription of statins, he trial a statin that has lower lipophilicity. One example is pravastatin, which is highly hydrophilic and less likely to cross the blood-brain barrier. Some patients have shown that changing from Simvastatin to pravastatin leads to a normalisation of memory impairment (Orsi et al., 2001; Wagstaff et al., 2003).

Although adverse events (AEs) in statin use are rare, in a meta analysis of 36,062 persons receiving statins and 35,046 receiving a placebo, pravastatin was found to produce less AEs than atorvastatin, and equal to the incident of AEs in simvastatin and lovastatina (Silva et al., 2006). Fluvastatin was identified as having the least risk but does not appear to have the same hydrophilic properties of pravastatin. Pravastatin and simvastatin are also extensively studied in follow up drug trials, accounting for 86% of studies, so incidence of AEs may appear higher in these drugs than what would normally be expected (Silva et al., 2006).

References

King, DS, Wilburn, AJ, Wofford, MR, Harrell, TK, Lindley, BJ, and Jones, DW (2003). Cognitive impairment associated with atorvastatin and simvastatin. Pharmacotherapy , 23 , 1663-1667.

Orsi, A, Sherman, O, and Woldeselassie, Z (2001). Simvastatin-associated memory loss. Pharmacotherapy , 21 , 767-769.

Silva, MA, Swanson, AC, Gandhi, PJ, and Tataronis, GR (2006). Statin-related adverse events: A meta-analysis. Clinical Therapeutics , 28 , 26-35.

Wagstaff, LR, Mitton, MW, Arvik, BM, and Doraiswamy, PM (2003). Statin-associated memory loss: analysis of 60 case reports and review of the literature. Pharmacotherapy , 23 , 871-880.

*The case examples are based on clinical experience but are dissimilar from real cases. The examples provided are for illustrative purposes only and any resemblance to a real life case is of coincidence.