Atorvastatin dosage

Elderly In patients older than 70 years of age, the AUC of lovastatin, pravastatin, and simvastatin is increased. Pravastatin does not need dosage adjustment. The safety and efficacy of atorvastatin, rosuvastatin, and lovastatin extended-release in patients 70 years of age and older were similar to those of patients younger than 70 years of age. Elderly patients (65 years of age and older) demonstrated a greater treatment response in respect to LDL-C, total-C and LDL/HDL ratio than patients younger than 65 years of age. 

The adverse effects of statins have been reviewed in the light of the ever increasing dosages that are being used to lower LDL cholesterol to a minimum (2). In another review high doses of atorvastatin and simvastatin were specially emphasized (3). 

In a comparison of atorvastatin with pravastatin, of 224 patients taking atorvastatin, two had clinically significant increases in alanine transaminase activity (32). They recovered during the next 4 months, one after withdrawal of atorvastatin and the other after a dosage reduction. Withdrawals due to adverse effects were similar in the two groups. One patient developed hepatitis while taking atorvastatin, but was able to tolerate simvastatin (33). The authors concluded that this adverse effect was not a class effect. Eosinophils in a liver-biopsy specimen pointed to an immunological mechanism. 

A 67-year-old man receiving a stable maintenance dosage of warfarin experienced an increased INR without bleeding when his atorvastatin therapy was switched to fluvastatin. His warfarin dosage was reduced and his INR stabilized. The fluvastatin was switched back to atorvastatin, and the warfarin dosage was increased to maintain the patient s goal INR (91). 

Healthy volunteers were given protease inhibitors and statins, and the authors concluded that simvastatin should be avoided and that atorvastatin could be used with caution in people taking ritonavir and saquinavir (111). Dosage adjustment of pravastatin may be necessary with co-administration of ritonavir and saquinavir. Pravastatin does not alter the pharmacokinetics of nelfinavir, and thus appears to be safe for co-administration. 

In a randomized crossover study rifampicin reduced the total AUC of atorvastatin and increased the Qnax of 2-hydroxyatorvastatin acid by 68% (101). It is advisable to increase the dosage of atorvastatin and preferable to administer it in the evening to guarantee adequate concentrations during the period of rapid cholesterol synthesis that occurs at night when rifampicin or other potent inducers of CYP3A4 are co-administered. 

Generic Name Atorvastatin Trade Name(s) Lipitor Dosage 10-80 mg once each day Primary Effect Decreases total cholesterol and plasma LDL-C may also decrease triglycerides and increase HDL-C somewhat... 

Atorvastatin is readily absorbed after the oral administration. Multiple daily dosages in the form of 2.5-80 mg capsules produce a maximum steady state concentration (Cmax) of 1.95-252 /ig/ml within 1-2 h. The AUC increases in proportion to the dose of atorvastatin, but the increase in Cmax is greater than for the proportional dose. The low systemic availability is attributed to the presystemic clearance in gastrointestinal mucosa and/or hepatic first pass metabolism. Food significantly... 

D.A. Shah, K.K. Bhatt, R.S. Mehta, M.B. Shankar, S.L. Baldania, T.R. Gandhi, Development and validation of a RP-HPLC method for determination of atorvastatin calcium and aspirin in a capsule dosage form, Indian J. Pharm. Sci. 69 (2007) 546-547. 

N. Jain, R. Raghuwanshi, D. Jain, Development and validation of RP-HPLC method for simultaneous estimation of atorvastatin calcium and fenofibrate in tablet dosage forms, Indian J. Pharm. Sd. 70 (2008) 263-265. 

St John s wort 1. Atorvastatin 2. Simvastatin 3. Lovastatin 1 blood levels and lipid-lowering effect Induction of metabolizing CYP3A4 enzymes, which metabolize simvastatin Avoid concomitant use if possible. Monitor response to simvastatin closely. Avoid sudden changes of the herb dosage... 

While that particular combination isn t currently on the market, one product (Caduet) combines Lipitor (atorvastatin) for cholesterol lowering and Norvasc (amlodipine) for blood pressure reduction. Caduet is available in a wide variety of dosages of both agents, allowing physicians to choose the one that would best suit a particular patient. That s much better than a fixed combination, since typically one size does not fit all. 

A study in 12 healthy women taking a combined oral contraceptive (ethi-nylestradiol/norethisterone 35 micrograms/1 mg) found that atorvastatin 40 mg daily increased the AUC of norethisterone and ethinylestradiol by about 28% and 19%, respectively, and increased their maximum plasma levels by 24% and 30%, respectively. These increases are only moderate and unlikely to be clinically important, but the manufacturers say that they should be considered when selecting an appropriate oral contraceptive dosage for women given atorvastatin. ... 

A smaUer study of atorvastatin alone at several dosages showed an incremental reduction in insuhn sensitivity, although of a low order—4% at the highest 80 mg/day dosage compared with either baseline or placebo [17% Similar findings have been reported for rosuvastatin HOMA-IR rose by as much as 45% at the highest dose, 40 mg/day [18. ... 

Metabolism Of considerable importance is the consistency with which small but important increments in the incidence of new diabetes mellitus have been reported in patients taking statins. This adverse effect was noted in the early Heart Protection Study with simvastatin (although it was not statistically significant) and in the ASCOT Trial with atorvastatin in both trials the hazard ratio for type 2 diabetes was 1.15 [31 ]. Atorvastatin at different dosages (10-80 mg/day) compared with placebo reduced insuhn sensitivity significantly within 2 months as glycemia increased. 

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