Combination regimens

In 2002, Grimes reported the efficacy of combination salicylic acid/TCA 10% peeling [1]. She treated patients with moderate to severe melasma with this combination regimen. In the series, nine patients were classified as Fitzpatrick skin type IV, eleven were skin type V, and seven were skin type VI. Many of the subjects included in the study had not responded to salicylic acid or glycolic acid peels. The concentration of salicylic acid was 20 and 30%, and the TCA concentration was 10%. A series of four peels was performed at 2-week intervals. Thirty percent of the patients experienced moderate improve-... 

There are few contraindications to combination salicylic acid/TCA peeling. The combination regimen is tolerated in all skin types and all ra-cial/ethnic groups. General contraindications include salicylate hypersensitivity unrealistic patient expectations active inflammation/der-... 

Combination Regimens Cefazolin or cefuroxime plus Meropenem Third- or fourth-generation... 

Monotherapy is equivalent to combination therapy once a causative pathogen has been identified. Empiric therapy should include combination regimens to ensure coverage of causative organisms. 

Paclitaxel also may be given concurrently with doxorubicin or epirubicin as a combination regimen. Pharmacokinetic interactions make these regimens more difficult to give. 

Treatment can cause substantial toxicity, which differs depending on the individual agent, administration method, and combination regimen. Because a comprehensive review of toxicities is beyond the scope of this chapter, appropriate references should be consulted. 

Early administration of effective combination chemotherapy at a time of low tumor burden should increase the likelihood of cure and minimize emergence of drug-resistant tumor cell clones. Combination regimens have historically been more effective than single agent chemotherapy (Table 61-1). 

Combination regimens produce objective responses in approximately 60% of patients previously unexposed to chemotherapy, but complete responses occur in less than 10% of patients. The median duration of response is 5 to 12 months the median survival is 14 to 33 months. 

Administration method affects clinical activity and toxicity. 5-FU is administered by IV bolus once weekly or daily for 5 days each month, or by continuous IV infusion. Efficacy evaluations favor continuous infusion 5-FU but none of the combination regimens with leucovorin has proven superior with regard to overall patient survival. 

Standard combination regimens (e.g., CHOP) yield disappointing results. Newer approaches including dose-adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin), and rituximab-containing combination chemotherapy are promising. 

Malaria parasite has developed resistance to many of these so-called quinoline antimalarials rendering them completely obsolete. This situation has forced the use of combination regimens that consists of a mixture of two or more antimalarial active ingredients this approach has proven to work better than monotherapies, but often is only a temporary soulu-tion. Nevertheless, quinine remains a very effective drug, with only few treatment failures or resistance reported around the globe. 

Combination regimens are designed in accordance with substance-specific development of resistance and pharmacokinetic parameters (CNS penetrability, neuroprotection, dosing frequency). 

Continuous combined regimen - Apply twice weekly during a 28-day cycle. 

Dosing guidelines Alert patients that frequently observed adverse events, such as mild to moderate Gl disturbances and paresthesias, may diminish as therapy is continued. In addition, patients initiating combination regimens with ritonavir and nucleosides may improve Gl tolerance by initiating ritonavir alone and subsequently adding nucleosides before completing 2 weeks of ritonavir monotherapy. 

Fatal and nonfatal pancreatitis has occurred during therapy with didanosine alone or in combination regimens in treatment-naive and treatment-experienced patients, regardless of degree of immunosuppression. Suspend didanosine in patients with suspected pancreatitis, and discontinue therapy in patients with confirmed pancreatitis (see Warnings). 

HIV co-infection - The formulation and dosage of lamivudine in Epivir-HBVare not appropriate for patients dually infected with HBV and HIV. If lamivudine is administered to such patients, use the higher dosage indicated for HIV therapy as part of an appropriate combination regimen. 

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