Tapentadol and Tramadol are both opioid pain medications, but they have some differences in terms of their chemical structure and effects.

1. Chemical Structure: Tapentadol is a centrally acting synthetic analgesic with dual mechanism of action, combining opioid receptor agonism and norepinephrine reuptake inhibition. Tramadol, on the other hand, is a centrally acting opioid analgesic that primarily works by binding to mu-opioid receptors and inhibiting the reuptake of serotonin and norepinephrine.

2. Potency: Tapentadol is generally considered to be more potent than tramadol in terms of pain relief.

3. Controlled Substances: Tapentadol is regulated as a Schedule II controlled substance in the United States, which means it has a higher potential for abuse and addiction compared to tramadol. Tramadol, however, is classified as a Schedule IV controlled substance in the US.

Regarding the countries where the use of these medications is banned or restricted, it varies from country to country. Some countries have strict regulations in place to control the misuse and abuse of opioid medications.

For example, in several European countries, including Sweden, Norway, and Denmark, Tapentadol is not available for human use. Tramadol is also more strictly controlled in some countries due to its potential for abuse. In the United Arab Emirates, for instance, tramadol is classified as a controlled substance and requires special authorization for use.

These medicines should not be used without a prescription and medical expertise for several reasons:

1. Potential for Abuse and Addiction: Both tapentadol and tramadol are opioids, which can be habit-forming and lead to dependence if misused or taken in high doses.

2. Side Effects and Safety Concerns: Opioid medications can cause various side effects such as drowsiness, dizziness, respiratory depression, constipation, and nausea. They can also interact with other medications and medical conditions.

3. Proper Dosage and Monitoring: Opioids should be used under medical supervision to ensure the appropriate dosage, duration, and monitoring for potential side effects and complications.

Using these medications without a prescription and medical expertise is considered risky, as individuals may not have the necessary knowledge or understanding of their potential risks and benefits. It is important to consult with a healthcare professional for a proper evaluation and prescription if these medications are required for pain management.