I. How to administer drugs for cancer pain treatment
According to the World Health Organization (WHO) guidelines for three-step pain relief treatment for cancer pain, the following five basic principles should be followed in drug treatment for cancer pain patients.
(1) Oral drug administration. Oral administration is the most common route of drug delivery. For patients who are not suitable for oral administration, other routes of drug delivery can be used, such as subcutaneous injection of morphine, patient-controlled analgesia, transdermal patches, etc. Li Hui, Department of Medical Oncology, People’s Hospital of Inner Mongolia Autonomous Region
2）Dosing according to the step. It means that analgesic drugs of different strengths should be selected in a targeted manner according to the patient’s pain level. The efficacy of three-step pain relief program: it can make 90% of cancer patients get effective pain relief, and more than 75% of advanced cancer patients can have their pain relieved.
①Mild pain: NSAIDs (non-steroidal anti-inflammatory drugs) Estradine Paracetamol Fotarol
②Moderate pain: weak opioids can be used, and NSAIDs can be combined with OxyContin and Chimantin
③Severe pain: strong opioids (Mescaline OxyContin) may be used and may be combined with reactions, and strong opioids may also be considered for mild and moderate pain. If the patient is diagnosed with neuropathic pain, tricyclic antidepressants or anticonvulsants should be preferred, etc.
3) Timely administration of medication. Refers to the regular administration of pain medication at prescribed time intervals. Timely administration helps to maintain a stable and effective blood concentration. At present, the clinical use of controlled-release drugs is becoming increasingly widespread, with emphasis on controlled-release opioid drugs and non-steroidal anti-inflammatory drugs.
The use of opioids in combination with NSAIDs can enhance the analgesic effect of opioids and reduce the dosage of opioids. If a good analgesic effect can be achieved and there is no serious adverse for the pain relief method of basic medication, immediate release opioids can be given for symptomatic treatment when titration and outbreak pain occur.
4）Individualized drug administration. It refers to the development of individualized medication regimen according to the patient’s condition and the dose of cancer pain relief drugs. When opioids are used, there is no ideal standard dose of opioids due to individual differences, and sufficient doses of drugs should be used according to the patient’s condition to provide pain relief. Also, the nature of neuropathic pain should be identified and the possibility of combination medication should be considered.
5) Attention to specific details: Patients on pain medication should be monitored and their response closely observed. Objective: Patients get the best efficacy with minimal side effects and improve the quality of life of patients.
NCCN Titration and maintenance of opioids: The general principle is to calculate increments based on the total dose of opioids used in the previous 24 hours, increase the dose administered on time and as needed, and the rate of dose increase should refer to the severity of symptoms. The next day’s total fixed dose = the total fixed dose of the previous 24 hours + the total titrated dose of the previous day, the next day’s titrated dose is 10%-20% of the total fixed dose of the previous 24 hours. Adjust the dose day by day according to the law until the pain score is stable at 0-3.
(i) For pain scores 7-10, consider increasing the total fixation by 50%-100%.
② pain score 4~6, consider increasing 25%~50% of the total immobilization amount.
③ Pain score 1~3, consider increasing 25% of total fixation.
Continuous analgesia q12h prescription, no ceiling effect (no extreme amount, mescaline, oxycontin pain relief effect is strong), domestic maximum morphine dosage: 1200mgQ24h.
Neuropathic pain pain relief prescription recommendations.
Anticonvulsants – gabapentin 100mg-300 mg/d to start (900-3600 mg/d)
– Pregabalin dose changed to 150-300 mg/d divided into 3 doses
Antidepressants – Amitriptyline 25mg qd starting
– Dose of venfaraxine changed to 50-75 mg/d divided into 2-3 doses (75 C 225) mg/d
– Duloxetine dose changed to 30-60 mg/d (60-120 mg/d)
Topical medication – lidocaine patch – 1% diclofenac sodium gel or patch 180 mg qd or BID
II. Treatment and care of side effects of analgesic drugs
1. Constipation: Generally tolerable, drinking more water, fibrous food, prophylactic use of laxatives, contact laxatives (senna, phenolphthalein) is required for long-term medication. Osmotic laxatives (lactulose, magnesium sulfate) to increase the amount of laxatives, if necessary, enemas, reduce the dose of opioids, combined with other painkillers, opioids in rotation.
2, nausea, vomiting: women, non-ambulatory patients, gastrointestinal tumors, combined with radiotherapy is likely to cause nausea, vomiting, the first day or the first few days after the drug is obvious, 1 week after the self-relieved, generally tolerable. Communicate with the patient in advance and use antiemetics. Mild: Gastrofacial, chlorpromazine, etc. (preventive medication); severe: 5-HT3 antagonists (therapeutic medication).
3. Drowsiness: A few patients may experience drowsiness during the first few days of medication, which can be tolerated after a period of time. Reason: Long-term pain leading to insomnia, manifestation after ideal pain control; alert to drug overdose if symptoms continue to worsen.
4, respiratory depression: respiratory depression occurs when pain is rapidly relieved and pain stimulation is not sufficient to counteract the sedative effect of opioids. Prevention: start with small doses, do not crush, chew or cut in half the extended-release tablets; medical workers and family members closely observe the patient’s sanity and breathing to detect abnormalities in a timely manner.
Treatment: stop opioids; establish a clear airway; assist ventilation breathing; respiratory resuscitation, naloxone 0.4mg + NS10ml IV slow, naloxone 2mg + NS (GS) 500ml IV drip or add stimulants (caffeine 100-200mg q6h po, etc.).
5, difficult urination: mostly occurs in male patients, especially patients with prostatic hyperplasia, the simultaneous use of sedatives, anesthesia will increase the risk of urinary retention after surgery.
Treatment measures: avoid simultaneous use of sedatives; avoid overfilling the bladder; gradually reduce the amount of drugs; induce urination (massage or hot compress bladder area); give the patient good time and space to urinate; retain catheterization if necessary.
6. Prevent opioid withdrawal symptoms. After the cause of cancer pain is controlled and the pain disappears, the dosage of opioids can be gradually reduced. For long-term high dose users, sudden discontinuation may lead to withdrawal syndrome, so the dosage should be gradually reduced, initially by 25~50% in two days, and then by 25% every two days until the daily dosage is reduced to 30~60mg.