Effective Pain Management of Postherpetic Neuralgia Using a Combination of Analgesics and Conservative Measures

Abstract

Postherpetic neuralgia (PHN) is characterized by persistent pain following the resolution of a herpes zoster rash. PHN is often resistant to treatment and can significantly reduce the patient's quality of life. Effective symptom relief is crucial and various treatments, including pharmacotherapy, have been attempted. Given that symptoms can persist for a prolonged period, they can substantially affect the physical and mental well-being of the patients. A 73-year-old man developed herpes zoster while undergoing treatment for a head angiosarcoma. Despite the resolution of the rash, the pain persisted, leading to the diagnosis of PHN. Treatment was initiated with a range of medications, including mecobalamin, pregabalin, and a combination of tramadol and acetaminophen, along with general pain relievers standardized as WHO Step 1 medications, which include acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs). However, achieving adequate pain control is challenging and results in frequent hospitalizations. Due to the patient's depression and the concurrent use of a selective serotonin reuptake inhibitor, duloxetine hydrochloride could not be prescribed. Instead, opioid therapy with continuous fentanyl citrate infusion was initiated. Eventually, the treatment was switched to oxycodone hydrochloride, which successfully stabilized the patient's symptoms. The use of conservative measures such as hot compresses also contributes to symptom relief. Alleviating pain symptoms using a combination of pharmacotherapeutic and non-pharmacological treatments is extremely important.

Keywords: duloxetine hydrochloride; hot compress; opioids; oxycodone hydrochloride; postherpetic neuralgia; pregabalin.

Figure 1. Physical examination on admission.

(A) Examination of the patient’s back revealed a cluster of vesicles and erythema, predominantly on the upper left side. (B) The left upper limb showed scattered erythema, predominantly on the anterior elbow.

Figure 2. Medication during the first period of hospital admission.

Mecobalamin was continued without changing the dose and pregabalin was administered along with a combination of tramadol and acetaminophen. On day 12 of hospitalization, the pregabalin dose was increased to 300 mg/day, and the patient was discharged on day 13.

Figure 3. Medication during the second period of hospital admission.

The introduction of opioids on day four after admission, along with the use of a hot compress on day six, was noteworthy.

Figure 4. An 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) performed just prior to the third period of admission.

(A) Left-sided head and (B) left anterior neck showing strong accumulation of FDG from the skin to deeper tissues.

Figure 5. Medication during the third period of hospital admission.

Five medications and one non-pharmacological intervention were administered. Continuous injections of oxycodone hydrochloride were administered and switched to oral medications when pain control was achieved. The patient was eventually switched to a fentanyl patch and discharged.