Antiemetics, such as 5HT3 antagonists (e.g. ondansetron and granisetron) and dopamine antagonists (e.g. metoclopramide), are widely used in clinical care to prevent and treat nausea and vomiting, for example postoperatively or during chemotherapy. Research shows that antiemetics administered enterally (e.g., orally or rectally) at an equivalent dose usually have a similar effectiveness and safety to those administered intravenously (IV) (1-2).

The oral/rectal route contributes to greater comfort and autonomy. In addition, the use of oral/rectal medication is more cost-effective and sustainable, because fewer disposable materials are required than intravenous administration (3). In situations where oral administration is not feasible, such as severe nausea or vomiting, rectal administration may sometimes still be chosen. IV administration is only eligible if this is not possible. This is further detailed in the NVZA monographs (4-6).

To treat postoperative pain, intravenous (IV) acetaminophen is usually administered. However, research shows that oral (PO) administration is equally effective and more sustainable in most patients. A systematic review of 14 studies shows that there is no convincing difference in the analgesic effect between IV and oral acetaminophen at different times after surgery (1). However, the environmental impact varies considerably: CO2 emissions from IV administration are up to 16x higher (2). Where an oral administration of 1 gram of acetaminophen from a blister results in the emission of approximately 38 grams of CO₂ eq., this can be up to 628 grams when administered IV, depending on the packaging and administration material (2).

In most patients, acetaminophen can be administered orally, as described in the NVZA Monograph 'Paracetamol' (3). The paracetamol challenge demonstrated that IV acetaminophen administration can be reduced by at least 25%, saving staff time, costs and environmental impact (4). These results underline deployment at a larger scale.

Inhalation medications are used in the treatment of asthma and COPD. In the Netherlands, more than 1.4 million people use inhalation medications every year, including bronchodilators, such as short- and long-acting β2 sympathomimetics and parasympatholytics, and inhaled corticosteroids (1). There are various types of inhalers available, including dose aerosols, powder inhalers, and soft mist inhalers. These vary greatly in environmental impact because dose aerosols contain propellants, such as HFA-134a, which has a 1500 times stronger greenhouse effect than CO₂ (2).

In some countries, powder inhalers are already prescribed more often. For example, the proportion of dose aerosols is lowest in Sweden (± 10%), highest in England (± 70%) and around 50% in the Netherlands (2, 3). If the Netherlands were to follow the Swedish example, a significant amount of CO₂ emissions could be prevented (2, 3). This is feasible because powder inhalers and soft mist inhalers are an effective alternative for most adult asthma and COPD patients, provided the inhalation technique is used correctly (4). In addition, more and more dose aerosols based on more sustainable propellants will come on the market in the coming years. This can also reduce the greenhouse gas emissions of inhalation medication.

To encourage doctors and pharmacists to prescribe climate-friendly inhalation medication, the Tranmural guideline for climate-aware prescribing of inhalation medication was developed by the Health Institute in collaboration with GPs, pulmonologists, paediatricians, pharmacists and the Lung Fund (4). To make a real impact, the guideline still requires inclusion in local formularies, so that the large-scale, unnecessary use of environmentally harmful inhalation medications can be reduced.

The prescription of multiple anticoagulant therapy (e.g. double or triple therapy with anticoagulants and antiplatelet agents) is complex and associated with an increased risk of bleeding. Patients often use these combinations temporarily, for example after acute coronary syndrome, percutaneous coronary intervention, or concomitant atrial fibrillation and stent implantation (1). European and Dutch guidelines therefore emphasize that double or triple therapy is never indicated for life, but always has a limited treatment period, depending on the clinical situation and the individual balance between the risk of bleeding or an ischemic event (1).

In practice, however, it appears that these drugs are regularly used for too long or are continued without a current indication, which significantly increases the risk of serious, preventable bleeding. For example, research in Dutch pharmacies showed that 14— 23% of patients who used dual anticoagulation no longer had a valid indication (2). During hospitalization, it was found that more than 40% of patients with multiple anticoagulant therapies used these combinations incorrectly (3). This risks bleeding complications, and thus unnecessary hospital admissions (4), but also contributes to unnecessary costs and environmental impact.

To prevent this, clear communication during dismissal and transfer is crucial. Explicitly sharing the indication and the intended treatment duration with primary care (general practitioner and pharmacist) enables follow-up care providers to continue treatment responsibly or to stop it in time. This contributes to medication safety, reduces the risk of complications and prevents unnecessary drug use.