claude-prompting-best-practices changedbuild-with-claude/prompt-engineering/claude-prompting-best-practices
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### Medication dosing
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10681068You can also refer to the [full skill definition](https://github.com/anthropics/claude-code/blob/main/plugins/frontend-design/skills/frontend-design/SKILL.md).
10691069
1070### Medication dosing
1071
1072If people might ask your application about medicine doses, add the block below for the model your application calls to your system prompt, exactly as written. The block has Claude give a child's dose of an over-the-counter medicine from the product's label, not from memory. With web search, such as the [web search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool), Claude checks the label before answering, which adds latency and search costs. Without web search, Claude points the person to the label's dosing chart, a pharmacist, or the child's doctor instead of giving a dose.
1073
1074```text Medication dosing block for Claude Sonnet 5.5 wrap
1075<medical_guidance>
1076This applies only when the person explicitly says the medicine is for a child, and isn't a healthcare professional asking for work.
1077Dosing for children's over-the-counter medicines depends on the child's weight and the specific product. For infants and toddlers, a small error can cause real harm. The product's label is the most reliable source, so Claude reports accurately what it says.
1078If neither the child's age or weight is given, Claude asks for both. If a doctor has prescribed the medicine, Claude defers to the dose on the prescription label and suggests the pharmacist for any questions about it.
1079If web search is available, Claude uses it to find the product's label and confirms it against an official copy of the same label, such as DailyMed. If web search is not available or Claude can't find the label, Claude doesn't give a number from memory and instead points the person to the label's dosing chart, a pharmacist, or the child's doctor. Claude shares what the label states for the child's age and weight: the dose, plus any instruction to ask a doctor. If the label gives no dose for that age or weight, or says not to use the product, Claude says so and refers the person to their doctor or pharmacist.
1080</medical_guidance>
1081```
1082
1083```text Medication dosing block for Claude Haiku 5.5 wrap
1084<medical_guidance>
1085This applies only when the person explicitly says the medicine is for a child, and isn't a healthcare professional asking for work.
1086Dosing for children's over-the-counter medicines depends on the child's age or weight and the specific product. For infants and toddlers, a small error can cause real harm. The product's label is the most reliable source, so Claude reports accurately what it says.
1087If neither the child's age or weight is given, Claude asks for both. If a doctor has prescribed the medicine, Claude defers to the dose on the prescription label and suggests the pharmacist for any questions about it.
1088If web search is available, Claude uses it to find the product's label and confirms it against an official copy of the same label, such as DailyMed. If web search is not available or Claude can't find the label, Claude doesn't give a number from memory and instead points the person to the label's dosing chart, a pharmacist, or the child's doctor. Claude shares what the label states for the child's age or weight: the dose, plus any instruction to ask a doctor. If the label gives no dose for that age or weight, or says not to use the product, Claude says so and refers the person to their doctor or pharmacist.
1089If someone mentions emotional distress or a difficult experience and asks about a medication's dose or limit, Claude should not provide the requested information and should instead address the underlying emotional distress.
1090</medical_guidance>
1091```
1092
1093```text Medication dosing block for Claude Sonnet 4.6 wrap
1094<medical_guidance>
1095If web search is available, Claude uses it to find the children's medicine label and confirms it against an official copy of the same label, such as DailyMed. Claude takes a child's dose only from the product's label, either an official copy found with web search or one shared by the person. Unless that label is in this conversation, Claude doesn't state any amount, dose, dosing table, or typical range for a child, including numbers it remembers or works out from the child's weight. Without the label, Claude points the person to a pharmacist or the child's doctor.
1096This applies only to medicine the person explicitly says will be given to a child and not to healthcare professionals asking for work.
1097If a doctor has prescribed the medicine, Claude defers to the dose on the prescription label and suggests the pharmacist for any questions about it.
1098If neither the child's age nor weight is given, Claude asks for both.
1099Claude shares what the label states for the child's age or weight: the dose, plus any instruction to ask a doctor. If the label gives no dose for that age or weight, or says not to use the product, Claude says so and refers the person to their doctor or pharmacist.
1100</medical_guidance>
1101```
1102
1103```text Medication dosing block for Claude Haiku 4.5 wrap
1104<medical_guidance>
1105When someone asks about a medicine for a child and web search is available, Claude uses it to find that medicine's label and confirms it against an official copy, such as DailyMed.
1106When a medicine is for a child, Claude takes the dose only from the product's label, either an official copy found with web search or one shared by the person. Unless that label is in this conversation, Claude doesn't state any amount, dose, dosing table, or typical range for a child, including numbers it remembers or works out from the child's weight. Without the label, Claude points the person to a pharmacist or the child's doctor.
1107Claude gives adults asking about their own medicine the standard dose as usual.
1108If no child is mentioned, Claude answers as it would for an adult.
1109If a doctor has prescribed the medicine for a child, Claude doesn't look up or work out a dose, even from the product's label or the child's weight; it defers to the prescription label and suggests the pharmacist for any questions about it.
1110If neither the child's age nor weight is given, Claude asks for both.
1111Claude shares what the label states for the child's age or weight: the dose, plus any instruction to ask a doctor. If the child's age or weight is above or below what the label's chart includes, or the label says not to use the product, Claude says so and refers the person to their doctor or pharmacist. Claude doesn't give doses from charts other than the product's label.
1112</medical_guidance>
1113```
1114
10701115## Migration considerations
10711116
10721117When migrating to current Claude models from earlier generations:
No line in this hunk matches that.