First some facts. Since 1979, when the Government took office, the prescription charge has risen more than 27-fold. From 20p then, it will be pounds 5.50 in April. Had it risen in line with inflation, it would be a tenth of that figure. The charge raises a little more than pounds 300m a year for the Treasury.
Paradoxically, however, many more prescriptions aredispensed free. In 1979, 40 per cent were paid for. The other 60 per cent went chiefly to people on benefits, the elderly and children, all of whom are exempt. This year, more than 80 per cent will be free - largely the result of an ageing population and higher unemployment.
Yet despite this massive extension of free prescribing, the rate at which the charge has risen has produced painful anomalies. The average NHS prescription costs about pounds 9.30 to dispense. But that average includes drugs that cost pounds 20 and more. Many are much cheaper, so much so that half cost less - often much less - than the pounds 5.50 charge, a fact that increases the sense that the charge has ceased to be a contribution and become a tax.
For those on marginal incomes, the high charges can be an impossible burden. A visit to the doctor often produces a prescription for two, three or four items, and every pharmacist has harrowing tales of people plaintively asking which item they can do without, to cut down on a pounds 15 to pounds 20 bill.
This is bad health care. And it is worse economics if the patient ends up returning to the doctor, or worse still, in hospital. Even the prescription "season tickets" (from April, pounds 28.50 for four months and pounds 78.40 for a year) are not cheap for the millions whose earnings are less than pounds 200 a week.
The current charging system is also riddled with arbitrary medical exemptions, the result of one-off historic decisions to exempt this group or that. Diabetics and those with Addison's disease are exempt, for example. But those with cystic fibrosis or Parkinson's disease are not. As a result, a diabetic with chronic bronchitis receives all prescriptions free, but a chronic bronchitic with heart failure does not. And so on.
Finally, such a high charge has led people to lie about their entitlement to free prescriptions. Prescription fraudcosts pounds 30m a year and rising, according to the Department of Health - a sum that has led it, at unknown cost, to impose more bureaucracy on pharmacists and patients in an attempt to reduce the scale of loss.
So what should be done? Abolition of the charge is unlikely. The Government won't give up the pounds 300m and Labour has long since dropped manifesto pledges to end NHS charging.
The alternative is to recognise that society has changed and to charge more people less for their medicines. The logic for this is that by far the biggest exempt group - the elderly - have long since ceased to be chiefly the poor elderly of the 1950s and 1960s. Their income, thanks in large measure to the growth of occupational pensions, has risen faster than the average since 1979.About 15 per cent of pensioners now depend on income support. And while one child in three lives in a family dependent on income support, many more parents could pay if the charge were less exorbitant and seen to be fairer.
On the Government's published figures, the sums are hard to do precisely. But they suggest that if children and the elderly were to lose their blanket exemption and instead be assessed according to the existing low-income schemes, the prescription charge could be slashed to around pounds 1.50 while still bringing in the Government's pounds 300m.
More importantly, the price of season tickets would tumble - to around pounds 7.50 for four months and pounds 21 for a year.
Some drugs would still cost less than the prescription charge but by a matter of pence, not pounds. The incentive for fraud would go. And the medical anomalies would appear less stark.
It would, of course, upset the grey vote. But it would undoubtedly be fairer.