Main Research Findings

Promethazine is a medication commonly used to treat nausea and vomiting. However, promethazine can cause a variety of side effects. 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects. 3 shows that promethazine, as a histamine H1 receptor blocker, can effectively reduce the catecholamine surge and organ injury after severe burns. 2 shows that promethazine is effective in combination with promotility drugs such as cisapride for the treatment of gastroparesis. 4 shows that promethazine induces autophagy-associated apoptosis in chronic myeloid leukemia cells by activating AMPK. 17 suggests that promethazine, a potentially inappropriate medication according to the Beers criteria, may be associated with an increased risk of unplanned hospitalization in older adults. 1 shows that promethazine, as a drug countermeasure for space motion sickness, may adversely affect working memory. 19 suggests that promethazine is tolerable with high-dose rate brachytherapy and side effects can be managed. 7 shows that first-generation antihistamines, including promethazine, are still widely used, but these drugs can cause significant sedation due to their ability to cross the blood-brain barrier. shows that many antiemetics, including promethazine, are used to prevent postoperative nausea and vomiting, but it is unclear which drug is most effective with the fewest side effects. 10 shows that promethazine is equally effective in treating uncomplicated nausea and vomiting in the emergency department compared to prochlorperazine. 27 shows that psychotropic medications, including promethazine, are associated with a higher risk of urological side effects. 24 shows that promethazine is sometimes used for rescue treatment of acute migraine in the emergency department. shows that promethazine can cause respiratory depression in newborns. shows that promethazine, used as a motion sickness medication, may be more effective when combined with melatonin. 14 shows that the safety of rapid infusion of rituximab, which may include promethazine, has been evaluated. 22 shows that first-generation H1 antihistamines, including promethazine, have been detected in the bodies of pilots who died in aviation accidents. shows that acidic agents, such as promethazine, can cause edema, sloughing, and necrosis due to cellular dehydration. 12 shows that sedatives, including promethazine, can be used to reduce anxiety and pain before oocyte retrieval. shows that promethazine is sometimes used in combination with morphine for patient-controlled analgesia (PCA). 11 shows that sedatives, including promethazine, can be used to control aggressive behavior in patients with mental illness. 23 shows that promethazine may affect the function of esophageal sphincters in cats. 16 shows that promethazine has the potential for phototoxicity and photoallergy. 25 shows that promethazine is sometimes used for rescue treatment of acute migraine in the emergency department. 5 shows that promethazine is involved in drug-drug interactions that can cause myopathy. 18 shows that promethazine is sometimes used for sedation and analgesia in pediatric dental patients. 15 shows that promethazine can be used to prevent anaphylactic reactions to etoposide. 8 shows that promethazine can adversely affect psychomotor performance in pilots.

Reasons for Side Effects

Side effects of promethazine are primarily due to its antihistamine and sedative properties. Promethazine blocks histamine H1 receptors, inhibiting histamine-induced vasodilation and increased capillary permeability. However, this effect can cause side effects such as drowsiness, dizziness, and impaired alertness. Promethazine also exerts sedative effects by acting on the central nervous system. This can cause side effects such as drowsiness, dizziness, and slowed reaction time. In addition, promethazine can act on the autonomic nervous system, causing side effects such as nausea, vomiting, constipation, and dry mouth.

Common Side Effects

Drowsiness

Promethazine can act on the central nervous system, causing drowsiness and fatigue. This is one of the most common side effects of promethazine. 7 shows that first-generation antihistamines, including promethazine, can cause significant sedation due to their ability to cross the blood-brain barrier.

Dizziness

Promethazine can affect the inner ear organs responsible for balance, causing dizziness. Promethazine can also lower blood pressure, which can contribute to dizziness. 7 shows that first-generation antihistamines, including promethazine, can cause significant sedation due to their ability to cross the blood-brain barrier.

Impaired Alertness

Promethazine can act on the central nervous system, impairing alertness and concentration. 7 shows that first-generation antihistamines, including promethazine, can cause significant sedation due to their ability to cross the blood-brain barrier.

Nausea

Promethazine can suppress stomach movement, leading to nausea. 10 shows that promethazine is equally effective in treating uncomplicated nausea and vomiting in the emergency department compared to prochlorperazine.

Vomiting

Promethazine can suppress stomach movement, leading to vomiting. 10 shows that promethazine is equally effective in treating uncomplicated nausea and vomiting in the emergency department compared to prochlorperazine.

Constipation

Promethazine can suppress bowel movement, leading to constipation. 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects.

Dry Mouth

Promethazine can suppress saliva production, leading to dry mouth. 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects.

Other Side Effects

Promethazine can also cause the following side effects: 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects. 27 shows that psychotropic medications, including promethazine, are associated with a higher risk of urological side effects. shows that promethazine can cause respiratory depression in newborns. 16 shows that promethazine has the potential for phototoxicity and photoallergy.

• Palpitations
• Shortness of breath
• Rash
• Itching
• Hives
• Swelling
• Muscle pain
• Joint pain
• Vision problems
• Tinnitus
• Headache
• Dizziness
• Loss of consciousness
• Breathing difficulties
• Shock

Side Effect Management

Drowsiness

To prevent drowsiness from promethazine, it's crucial to avoid activities that require attention, such as driving or operating machinery. It's also important to be mindful of the timing of promethazine intake, with bedtime being the ideal time. 7 shows that first-generation antihistamines, including promethazine, can cause significant sedation due to their ability to cross the blood-brain barrier.

Dizziness

If you experience dizziness from promethazine, it's important to rest and avoid strenuous activities. Staying hydrated is also essential. 7 shows that first-generation antihistamines, including promethazine, can cause significant sedation due to their ability to cross the blood-brain barrier.

Impaired Alertness

If you experience impaired alertness from promethazine, it's crucial to avoid activities that require attention, such as driving or operating machinery. It's also important to be mindful of the timing of promethazine intake, with bedtime being the ideal time. 7 shows that first-generation antihistamines, including promethazine, can cause significant sedation due to their ability to cross the blood-brain barrier.

Nausea

If you experience nausea from promethazine, it's recommended to eat small meals frequently. Staying hydrated is also essential. 10 shows that promethazine is equally effective in treating uncomplicated nausea and vomiting in the emergency department compared to prochlorperazine.

Vomiting

If you experience vomiting from promethazine, it's essential to stay hydrated to prevent dehydration. If vomiting persists, it's crucial to consult with a doctor. 10 shows that promethazine is equally effective in treating uncomplicated nausea and vomiting in the emergency department compared to prochlorperazine.

Constipation

If you experience constipation from promethazine, increasing dietary fiber intake and staying hydrated can help. If constipation persists, it's important to consult with a doctor. 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects.

Dry Mouth

If you experience dry mouth from promethazine, it's crucial to stay hydrated. Chewing gum or sucking on candy can also be helpful. 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects.

Other Side Effects

If you experience any other side effects from promethazine, it's crucial to consult with a doctor. 9 shows that promethazine, prochlorperazine, and metoclopramide have common and potentially dangerous side effects. 27 shows that psychotropic medications, including promethazine, are associated with a higher risk of urological side effects. shows that promethazine can cause respiratory depression in newborns. 16 shows that promethazine has the potential for phototoxicity and photoallergy.

Comparison Across Studies

Similarities

Many studies show that promethazine can cause side effects such as nausea, vomiting, drowsiness, and dizziness. Additionally, it is suggested that promethazine should be used with caution in specific patient populations, such as older adults and newborns.

Differences

Research on promethazine side effects varies in terms of the targeted patient population and research design, leading to differing results. Consequently, comparing promethazine side effect research findings can be challenging. However, these studies clearly demonstrate that promethazine can cause various side effects.

Real-World Application Notes

Promethazine is an effective medication for alleviating symptoms like nausea and vomiting. However, because it can cause numerous side effects, it's crucial to follow a doctor's instructions when taking it. Notably, if you need to engage in activities that require focus, such as driving or operating machinery, avoid taking promethazine or ensure adequate rest afterward. If you experience drowsiness, dizziness, impaired alertness, or other side effects while taking promethazine, refrain from activities that demand attention and consult with a doctor. Moreover, promethazine should be used with more caution in specific patient populations, such as older adults and newborns.

Current Research Limitations

Research on promethazine side effects is still insufficient, particularly regarding its long-term impacts. Additionally, the extent to which promethazine side effects vary based on factors such as patient age, gender, build, and overall health remains largely unclear.

Future Research Directions

Further research on promethazine side effects is needed, especially to investigate its long-term effects, how these effects differ based on factors such as patient age, gender, build, and overall health, and ways to mitigate promethazine side effects.

Conclusion

Promethazine is an effective medication for treating symptoms like nausea and vomiting. However, it can cause a variety of side effects. Therefore, it's crucial to follow a doctor's instructions when taking promethazine. Furthermore, additional research is needed on promethazine side effects.