There are many combined methods. For example this one described below.
After fasting for six hours, take 8 mg of ondansetron or 10 mg of metoclopramide to prevent nausea and vomiting. Around the same time, drink 100 ml of strong alcohol, like vodka or whiskey, to slow digestion and help the body absorb everything more efficiently. About 45 minutes before, crush 5 to 10 oleander leaves and mix them into a high-fat liquid, like milk or oil, which slows stomach emptying and maximizes the absorption of its cardiac toxins. Thirty minutes before, consume 5 grams of Aconitum napellus root, preferably in an alcohol tincture, for rapid absorption through the mouth and intestines. If using powdered aconite, encapsulate it in gastro-resistant capsules to avoid stomach irritation that might trigger vomiting. Fifteen minutes before, take 10 mg of diazepam (Valium) or lorazepam (Tavor) to reduce anxiety and suppress any natural panic response. Five minutes before, move toward the train tracks, paying attention to early symptoms like tingling, dizziness, and the first irregularities in heartbeat as the toxins start taking effect. As the train approaches at over 100 km/h, position yourself on the tracks. By this point, the combination of oleander and aconite will have already begun severely disrupting the heart's function, making unconsciousness or cardiac arrest imminent. If the poison hasn't acted yet, the impact ensures there's no coming back.