The short version
- Radio Medical Denmark treated 9,458 seafarers from 2021 to 2023 and prescribed 11,698 medications; 77.9% of patients got at least one[1].
- Pain relief was 55.4% of all prescriptions, antibiotics 15.2% and eye or ear drops 8.7%[1].
- Physicians had 266 different medicines available across the chests they advised on, but only 111 were used even once[1].
- Rarely used is not removable: the authors say naloxone, atropine, activated charcoal, ethyl alcohol and phytomenadione must stay, because the conditions they treat are life-threatening[1].
The first study of what ships actually prescribe
Every chest list is a forecast. This is the first published check of the forecast against use. Thorsteinsdottir and colleagues analyzed three years of records from Radio Medical Denmark, the Danish maritime telemedical service, covering 9,458 patients[1]. They describe it as the first study of maritime prescription patterns at the level of individual medications[1].
| Measure[1] | Figure |
|---|---|
| Patients, 2021 to 2023 | 9,458 |
| Medications prescribed | 11,698 |
| Patients given medication | 77.9% (81.3% on merchant ships, 64.5% on oil platforms) |
| Prescriptions per patient | 1.24 on average (0 to 6) |
| Merchant ship crew share of patients | 63.5% |
| Average patient age | 38.66 years |
What gets used: the prescription league table
| Group or subtype[1] | Prescriptions | What it tells a chest planner |
|---|---|---|
| Paracetamol (antipyretic) | 3,500 | The single biggest line; never run short |
| NSAIDs (ibuprofen, diclofenac and others) | 2,540 | Second pillar of pain relief |
| Oral antibiotics | 1,690 | Infection is the second-largest group (15.2%) |
| Eye drops | 979 | Eye and ear care is 8.7% of all prescribing |
| Antihistamines | 431 | 13 different antihistamines were available |
| Opioids | 380 | Severe pain; 8 different opioids were available |
| Skin corticosteroids | 373 | Skin is 5.1% of prescribing |
| Dyspepsia treatments | 282 | Largest gastrointestinal line |
| Nasal medication | 202 | Common colds still need cover |
Pain relief alone was 6,488 prescriptions, 55.4% of the total[1]. Allergy and cardiac drugs each made up about 5% or less[1].
What sits in the chest and never gets used
Among medicines not used at all over three years, the most common were poisoning treatments such as activated charcoal, ethyl alcohol and phytomenadione, plus HIV medication, specific malaria treatments, most lotions and oral rehydration fluids[1]. The seasickness entry, hyoscine, recorded zero prescriptions[1].
Unused is not the same as unnecessary
The authors are explicit: naloxone, atropine, activated charcoal, ethyl alcohol and phytomenadione cannot realistically be removed despite irregular use, because the conditions they treat are life-threatening[1]. They suggest quinine and zidovudine/lamivudine could be considered for removal[1]. Antidote decisions also follow the cargo; see chemical tanker antidote requirements and naloxone on vessels.
Too many versions of the same drug
The study’s sharpest finding is duplication. Physicians could choose among 13 antihistamines, 8 opioids and at least 17 oral or intravenous antibiotics, because chests from different flags held different products[1]. The authors warn that so large an array is a potential source of medical errors, since both crew and prescribing physicians are less familiar with the dosing and side effects of so many drugs[1].
They also found gaps. Neither direct oral anticoagulants nor low-molecular-weight heparin were in the Danish chest, and intranasal pain relief, simpler for medical officers without formal training than intravenous treatment, was mostly absent[1].
The flag effect, visible in one year
The study caught a natural experiment. In 2023, Radio Medical Denmark began advising ships that sail under other flags and carry other chests[1]. Prescriptions of medicines not in the Danish chest rose from 5 in 2021 and 12 in 2022 to 156 in 2023[1].
| Year[1] | Prescriptions of non-Danish-chest medicines |
|---|---|
| 2021 | 5 |
| 2022 | 12 |
| 2023 | 156 |
Same doctors, same kind of patients, different chests, different prescribing. The authors say the overlap within drug groups stems from those different chest contents[1]. For a fleet under more than one flag, that is the argument for one fleet-wide core list layered under each flag’s legal minimum.
Why chests differ: the standard is old and not law in the US
The authors note the WHO International Medical Guide for Ships was last published in 2007, is followed by 86% of maritime stakeholders, and that work on a fourth edition, begun in 2021, has been put on hold[1]. MLC 2006 tells competent authorities to take that guide into account when setting chest contents and to inspect the chest at least every 12 months[3].
In the US there is no federal contents list at all: FDA has never suggested or recommended any particular procedure for supplying ships’ medicine chests[2]. That freedom is the opportunity. A US operator can build the chest from usage data instead of copying a list. For flag-driven lists, see ship medicine chest requirements by flag state.
Five ways to use this data on your own chest
- Stock deepest where use is heaviest: pain relief, antibiotics, eye care[1].
- Pick one product per need: one antihistamine, a short opioid list, a set antibiotic list, to cut the duplication the study flags[1].
- Keep the rare life-savers: antidotes stay even if they expire unused[1].
- Review gaps against your crew and route, such as anticoagulation and non-intravenous pain relief[1].
- Track your own usage and review it at each inspection[3]; expiry handling is in expired medicines on ships.
Opioids are the one group with federal rules attached. On US vessels they are held under a medical officer or master’s requisition; see 21 CFR 1301.25 explained.
Discovery Health MD rebuilds chests this way: a usage-based list with one product per need through ship medical chest management, a lawful opioid line through controlled substances management, and physician review of gaps for your crew and routes through maritime medical consulting. Send us your current chest list and we will compare it with this data.
Common questions
What medicines are used most on ships?
In 11,698 prescriptions by Radio Medical Denmark, paracetamol led with 3,500, then NSAIDs with 2,540 and oral antibiotics with 1,690[1].
How often do sick seafarers need medication?
77.9% of patients advised by Radio Medical Denmark were prescribed medication, averaging 1.24 prescriptions each[1].
How many different drugs are in ship medicine chests?
Across the chests in the study, 266 individual medications were available, but only 111 were used at least once in three years[1].
Can unused medicines be removed from the chest?
Not all. The authors say antidotes such as naloxone, atropine, activated charcoal, ethyl alcohol, and phytomenadione must stay despite rare use[1]. The full method is in how to stock a ship medicine chest.
Is there a standard list for ship medicine chests?
The WHO International Medical Guide for Ships was last published in 2007, and its update is on hold[1]. MLC tells flag authorities to take it into account[3]. The US sets no federal list[2].
Are seasickness tablets used much at sea?
In this dataset, the hyoscine seasickness entry recorded zero prescriptions over three years[1].
How many opioid options does a chest need?
The study found 8 opioid types available and flagged the overlap as a source of error[1]. A short, physician-set list is easier to dose safely; see controlled substance schedules for vessels.
