When you write a prescription, do you reach for the brand name or the generic? For most medications, the answer should be the generic - and there’s solid, up-to-date guidance to back that up. In the UK, NHS England expects clinicians to prescribe using the International Non-proprietary Name (INN) - the generic name - in at least 90% of cases. That’s not just a suggestion. It’s the standard. And for good reason.
Why Generic Prescribing Matters
Generic drugs aren’t cheaper because they’re worse. They’re cheaper because they don’t carry the marketing, patent, and R&D costs of the original brand. A pill of generic atorvastatin costs around £2.50 a month. The brand version, Lipitor, used to cost £30. Omeprazole? Generic is £1.80. Losec? £15. That’s an 80-85% drop in cost - with no drop in effectiveness. The NHS estimates that if every eligible prescription were written generically, it could save £1.3 billion a year. That’s money that can go toward more cancer screenings, mental health services, or hiring more GPs. And it’s not just about savings. Patients who pay less out of pocket are more likely to take their meds as prescribed. Studies show generic prescribing improves adherence by 8-12%, which leads to 15% fewer hospitalizations for conditions like high blood pressure or diabetes.How Generic Drugs Are Proven Safe
You might hear someone say, “But my cousin switched to generic and felt different.” That’s often not about the drug - it’s about expectation. The nocebo effect - where people feel worse because they believe something won’t work - accounts for about 30% of reported differences in patient surveys. Regulators don’t take chances. The FDA, EMA, and MHRA all require generics to prove they’re bioequivalent to the brand. That means the active ingredient must be identical, in the same amount, and absorbed into the bloodstream at the same rate and extent. For most drugs, the acceptable range is 80-125% bioequivalence. That’s not a loophole - it’s a scientifically proven window where the body responds the same way. And the manufacturing? Same standards. Generics must meet the same purity, potency, and quality controls as branded drugs. The only differences are in inactive ingredients - fillers, dyes, coatings - which rarely affect how the drug works.When You Should NOT Prescribe Generically
There are exceptions. And they matter. The British National Formulary (BNF) clearly outlines three categories where brand-name prescribing is still recommended:- Category 1: Narrow therapeutic index drugs - where small changes in blood levels can cause harm. These include warfarin, levothyroxine, phenytoin, carbamazepine, and digoxin. Switching brands here can lead to dangerous INR fluctuations or seizures.
- Category 2: Modified-release formulations - like theophylline or certain sustained-release opioids. The way the drug is released over time can vary slightly between manufacturers, and for some patients, that’s enough to cause problems.
- Category 3: Biologics and biosimilars - insulin, TNF inhibitors, monoclonal antibodies. These are complex molecules. The MHRA insists they be prescribed by brand name to prevent automatic substitution. Even small changes in manufacturing can trigger immune responses.
What the Evidence Says About Switching
Some concerns are real. A 2018 meta-analysis in Epilepsia found a 1.5-2.3% increase in seizure recurrence when patients on stable antiepileptic drugs were switched between generic versions - especially if they were switched multiple times. That’s why the American Epilepsy Society recommends avoiding unnecessary switches in these patients. For thyroid patients on levothyroxine, small variations in absorption can lead to TSH fluctuations. Many endocrinologists prefer to keep patients on the same brand - not because generics are unsafe, but because consistency matters. If a patient is stable on a brand, switching for cost alone isn’t always the right move. But here’s the key: these are exceptions. For the other 98% of drugs - antibiotics, statins, antidepressants, blood pressure meds - switching to generic is not just safe. It’s better.How to Talk to Patients About Generics
The biggest barrier to generic prescribing isn’t clinical - it’s perception. Patients worry. They think generics are “inferior.” A 2021 study showed that when doctors explained the rationale, patient acceptance jumped from 67% to 89%. So don’t just write “generic.” Talk about it. Use simple, clear language:- “This medicine has the same active ingredient as the brand you were on. It’s been tested to work the same way.”
- “It’s cheaper because it doesn’t have the advertising costs - not because it’s less effective.”
- “You’ll save about £12 a month. That’s £144 a year you can use for other things.”
How to Implement This in Practice
NHS England’s Generic Prescribing Toolkit gives a clear 4-step plan:- Audit - Use the Prescribing Analytics Dashboard to see what % of your prescriptions are generic. Most practices are at 85-90%. Aim for 92%+.
- Educate - Train your team on the three exception categories. Keep the BNF open on your computer.
- Set defaults - Make sure your electronic prescribing system is set to auto-fill the INN, not the brand name.
- Monitor - Check your prescribing data every quarter. Look for spikes in brand-name prescriptions - and ask why.