Patient-Tailored Combinations of Systemic and Topical Preparations for Localized Peripheral Neuropathic Pain: A Two-Case Report

This report describes two patients with peripheral neuropathic pain (PNP): a 43-year-old man with upper leg PNP and a 75-year-old woman with post herpetic neuralgia of the perineum and vagina. Pain was inadequately managed in both patients for a long time. A patient-tailored approach, including a combination of systemic and topical compounds, required multiple adjustments for each patient before finally achieving adequate pain control. The first patient achieved pain control with a combination of systemically-administered drugs: dipyrone (1 g 3 times a day), pregabalin (300 mg twice a day), duloxetine (60 mg once daily in the morning), and dextromethorphan (60 mg 3 times/day), plus topical compounds (10% ketamine, 5% lidocaine, and 10% ketoprofen) in penetrating enhancing gel, and sublingual ketamine (10 mg) for breakthrough pain. The second patient achieved optimal pain control with dipyrone (500 mg three times per day), pregabalin (150 mg twice a day), dextromethorphan (60 mg three times per day), plus topical compounds (10% ketamine, 0.3% clonidine, 5% diclofenac) in a penetrating enhancing gel. Notably, the individualized approach described herein was made possible through collaboration between a public health pain specialist and a private sector compounding pharmacist, highlighting the importance of such infrequent but, highly desirable collaborations.     

Nitrite and Nitrate Concentrations and Metabolism in Breast Milk,Infant Formula,and Parenteral Nutrition

Dietary nitrate and nitrite are sources of gastric NO, which modulates blood flow, mucus production, and microbial flora. However, the intake and importance of these anions in infants is largely unknown. Nitrate and nitrite levels were measured in breast milk of mothers of preterm and term infants, infant formulas, and parenteral nutrition. Nitrite metabolism in breast milk was measured after freeze‐thawing, at different temperatures, varying oxygen tensions, and after inhibition of potential nitrite‐metabolizing enzymes. Nitrite concentrations averaged 0.07 ± 0.01 μM in milk of mothers of preterm infants, less than that of term infants (0.13 ± 0.02 μM) (P < .01). Nitrate concentrations averaged 13.6 ± 3.7 μM and 12.7 ± 4.9 μM, respectively. Nitrite and nitrate concentrations in infant formulas varied from undetectable to many‐fold more than breast milk. Concentrations in parenteral nutrition were equivalent to or lower than those of breast milk. Freeze‐thawing decreased nitrite concentration ~64%, falling with a half‐life of 32 minutes at 37°C. The disappearance of nitrite was oxygen‐dependent and prevented by ferricyanide and 3 inhibitors of lactoperoxidase. Nitrite concentrations in breast milk decrease with storage and freeze‐thawing, a decline likely mediated by lactoperoxidase. Compared to adults, infants ingest relatively little nitrite and nitrate, which may be of importance in the modulation of blood flow and the bacterial flora of the infant GI tract, especially given the protective effects of swallowed nitrite.